FIRST  BOOKS  OF  -.NATURAL  HISTORY. 


ELEMENTS  OF  GEOLOGY 


PRP:PARED  FOR  THE  USE  OF 


SCHOOLS    AND    COLLEGES, 


ELLIOT, 

FOURTH   STREET. 

1845. 


W.  S.  W.  RUSCHENBFTIGER,  M.D. 

I, LOW  OF  THE  COLLEGE  OF  PHYSICIANS  ;  HOS.  l| 
UA  MEDICAL  SOCIETY;  MEMBER  OF  THE 
.\L  SCIENCES  OF  iT:  L,  ETC  ,  ETC. 


MILNE  EDWARDS  AND  ACHILLE  COMTE, 

PROFESSORS  OF  NATURAL  HISTORY- IN  THE  COLLEGES 


OF  HENRI  IV.,  AND  CHARLEMAGNE. 


: 


UNIVERSITY  OF  CALIFORNIA. 


FROM   THE    LIBRARY   OF 

DR.  JOSEPH   LECONTE, 

GIFT  OF  MRS.   LECONTE. 
No. 


Geology. 


RXJSCHENBERGER'S    SERIES. 


FIRST  BOOKS  OF  NATURAL  HISTORY, 


ELEMENTS    OF    GEOLOGY: 


PREPARED    FOR   THE   USE    OP 

SCHOOLS    AND    COLLEGES, 

BY 

W.  S.  W.  RUSCHENBERGER,  M.D. 

SURGEON   IN   THE   U.   S.    NAVY  ;     FELLOW   OF   THE   COLLEGE   OF   PHYSICIANS   OF 

PHILADELPHIA  ;    OF   THE    COLLEGE   OF  PHYSICIANS   AND   SURGEONS   OF   THE 

UNIVERSITY   OF   THE   STATE   OF   NEW   YORK  J    HON.    MEMBER   OF   THE 

PHILADELPHIA    MEDICAL    SOCIETY  J    MEMBER    OF   THE    ACADEMY 

OF  NATURAL  SCIENCES  OF  PHILADELPHIA  J  CORRESPONDING 

MEMBER   OF  THE   AMERICAN   INSTITUTE,    ETC.    ETC. 

FROM  THE  TEXT  OF 


F.    S.    B  E  U  D  A  N  T, 

.OYAL  ACADEMY  OF  SCIENCES  J   INSPECTOR 
OF  STUDIES,  ETC. 

MILNE  EDWARDS,  AND  ACHILLE  COMTE, 


OF  THE  ROYAL  ACADEMY  OF  SCIENCES  J   INSPECTOR  GENERAL 
OF  STUDIES,  ETC. 


WJCTH   THREE   HUNDRED   E 


PHILADELPHIA  : 
GRIGG    &    ELLIOT, 

NO.    9    NORTH    FOURTH    STREET. 

1846. 


Entered,  according  to  the  Act  of  Congress,  in  the  year  1843,  by 
W.  S.  W.  RUSCHENBERGER,  M.D., 

in  the  clerk's  office  of  the  District  Court  of  the  United  States  in  and  for  the 
Eastern  District  of  Pennsylvania. 


J.  Fagan,  btereotyper. 

T.  K.  &  P  G^  Collins,  Printers. 

(4) 


PREFACE 


THE  eighth  in  the  series  of  "  First  Books  of  Natural  History," 
comprises  the  Elements  of  Geology. 

The  volume  has  been  compiled  chiefly  from  the  work  of  F.  S. 
Beudant,  and  that  of  Milne  Edwards,  and  Achille  Cornte.  The 
works  of  other  writers  have  been  consulted,  and  freely  used ; 
amongst  them,  Ansted,  Lyell,  Mantel,  Murchison,  Trimmer,  Buck- 
land,  Bakewell,  De  la  Beche,  Lea,  Parkinson,  Phillips,  Dana, 
Percival,  Charles  T.  Jackson,  Henry  D.  Rogers,  Morton,  Conrad, 
&c.,  &c. 

The  numerous  illustrations,  to  the  execution  of  which  we  par- 
ticularly invite  attention,  were  engraved  by  MR.  G.  THOMAS,  of 
Philadelphia.  We  believe  better  wood-cuts  have  never  been 
engraved  in  the  United  States  for  any  work  of  the  kind,  and  as  a 
sample  of  the  art,  they  are  creditable  to  our  country. 

The  explanations  and  etymologies  of  technical  words  are  given 
as  they  occur,  either  in  the  text,  or  in  foot-notes ;  and  in  many,  if 
not  in  all  cases,  the  pronunciation  of  these  words  has  been  indi- 
cated by  accents.  An  ample  glossary,  which  will  be  found  suffi- 
ciently copious  for  the  general  reader,  is  also  appended.  When  it 
occurs,  the  Greek  omega  has  been  marked  thus  (d),  and  italics 
have  been  substituted  for  Greek  characters,  because,  it  is  presumed, 
many  who  may  use  this  volume  are  unacquainted  with  the  dead 
languages. 

It  is  believed  this  small  volume  contains  all  that  is  requisite  for 
acquiring  a  knowledge  of  the  Elements  of  Geology,  except  the 
desire  and  consequent  labour  of  the  student,  essential  elements  in 
the  acquisition  of  knowledge  of  every  kind.  Without  labour, 
knowledge  cannot  be  obtained ;  to  reach  the  goal,  the  road  must 
be  travelled,  no  matter  how  smooth  and  easy  it  may  be  made ;  there 

11  101308  (5) 


VI  PREFACE. 

is  no  royal  path  to  learning.  When  the  student  is  master  of  the 
information  contained  in  this  book,  he  will  be  fully  prepared  for 
reading,  advantageously,  voluminous  treatises,  and  the  various 
geological  reports  and  papers  almost  daily  issuing  from  the  press. 

All  knowledge  is  necessarily  communicated  from  one  person  to 
another,  through  the  medium  of  words,  or  signs.  When  branches, 
or  parts  of  knowledge,  or  ideas,  become  familiar  and  common,  the 
words  representing  them  cease  to  be  difficult.  Then  the  complaint 
about  "  hard  words"  ceases.  Few  persons  acquainted  with  the 
instruments,  complain  that  the  words  Thermometer,  or  Barometer, 
are  "  hard  ;"  the  first  is  familiar  to  all,  even  to  those  ignorant  of  its 
construction  and  numerous  practical  uses.  The  names  Quadrant 
and  Sextant  are  not  "  hard  words"  to  the  most  unlettered  seaman, 
and  we  may  remark,  in  passing,  that  the  science  of  navigation 
would  not  be  rendered  of  more  easy  acquisition,  if  those  instru- 
ments were  designated  by  the  more  familiar  names  of  Bob  and  Bill. 
The  votary  of  music  does  not  find  the  numerous  terms,  such  as 
clef,  minim,  semibreve,  crotchet,  or  sonata,  overture,  aria,  or 
pianissimo,  crescendo-,  forte,  &c.,  obstacles  in  acquiring  a  know- 
ledge of  the  science.  The  same  is  true  of  all  human  sciences. 
Each  has  its  technicalities  and  significant  names,  which  cannot  be 
changed  without  injury,  or  taken  away  without  increasing  the 
difficulties  of  acquiring  knowledge. 

The  names  and  terms  employed  in  Natural  History  are  very 
numerous,  but  most  of  them  are  very  significant  and  appropriate. 
[t  is  true,  some  are  of  doubtful  or  remote  meaning,  and  might  have 
been  better.  The  fashion  of  naming  natural  objects  after  dis- 
tinguished individuals,  might  be  safely  abandoned.  All  who  are 
so  fortunate  as  to  discover  a  new  genus,  or  species,  should  carefully 
select  a  name  for  it  significant  of  some  prominent  quality  or  attri- 
bute, so  that  the  generic  and  specific  names  would  be  together 
descriptive,  as  far  as  possible,  of  the  object. 

Hard  names  are  no  real  obstacles  to  the  acquisition  of  science, 
and  no  benefit  would  arise  by  departing  from  systematic  nomencla- 
ture in  elementary  works.  One  great  object  of  such  works,  is  to 
explain  the  meaning  of  the  names  and  terms  employed.  Nursery, 
or  "baby  talk,"  does  not  facilitate  a  child  in  learning  to  speak,  or 
in  acquiring  ideas ;  nor  would  the  study  of  geology  be  facilitated 


PREFACE.  Vll 

by  analogous  language.  Probably  Natural  History  has  been  made 
less  interesting  in  our  country,  and  has  been  less  beneficially 
studied,  in  consequence  of  attempts  to  employ  old  words,  already 
appropriated  to  well-known  things,  to  designate  new  objects. 

The  writer  trusts  the  above  remarks  will  be  sufficient  to  meet 
the  objections  of  all  those  who  cavil  about  "  hard  words." 

Besides  being  in  itself  very  interesting,  forming  as  it  were  the 
blossom  and  bloom  of  Natural  History,  a  knowledge  of  zo'ology 
and  botany  being  necessary  to  the  study  and  recognition  of  animals 
and  plants  in  the  fossil  state,  Geology  is  practically  useful  in  a 
high  degree.  To  agriculture,  and  many  of  the  mechanic  arts,  it 
is  of  great  advantage,  and  it  is  not  totally  useless  to  any  avocation 
or  pursuit.  A  competent  knowledge  of  Geology  better  enables  the 
architect  to  select  materials  for  buildings,  as  well  as  sites  for  their 
erection ;  the  engineer  learns  from  it  where  he  may  run  a  railroad 
or  canal  with  the  greatest  facility,  and  least  cost;  the  miner  is 
guided  in  the  pursuit  of  mineral  wealth,  metals,  or  coal,  with 
greater  certainty  of  success  when  assisted  by  this  noble  science, 
which  is  more  unerring  than  witch-hazel  or  diving  rod ;  it  facili- 
tates the  physician  in  the  study  of  climate,  and  opens  a  wide  field 
to  the  divine  for  pointing  out  the  wonders  of  the  creation,  and  the 
goodness  of  God. 

Before  its  natural  history  was  explored,  at  a  cost  of  more  than 
two  hundred  thousand  dollars,  voted  by  the  Legislature,  vast  sums 
of  money  were  spent  in  vainly  hunting  for  coal-mines  in  the  state 
of  New  York.  But  after  the  geological  surveyors  reported  that 
no  coal  could  ever  be  discovered  in  the  districts  they  had  examined 
(because  the  several  formations  constituting  the  surface  of  these 
districts  were  those  which  are  naturally  below  the  coal-bearing 
series),  these  wasteful  speculations  were  abandoned,  although  per- 
sons unacquainted  with  Geology  complained  that,  "not  satisfied 
with  their  inability  to  find  coal  themselves,  the  surveyors  had 
decided  that  no  one  else  would  ever  be  able  to  detect  any,  having 
had  the  presumption  to  pass  sentence  of  future  sterility  on  the 
whole  land,"  But  time  will  show  there  was  no  presumption  or 
guess,  but  the  sentence  of  the  geologists  was  a  positive  deduction 
from  their  science  —  a  deduction  that  has  saved  thousands  of 
dollars  to  individuals,  who  would  still  seek  for  coal  where  it  does 
not  exist,  were  it  not  for  a  knowledge  of  Geology. 


Vlll  PREFACE. 

In  order  to  study  Geology  with  greater  facility  and  success, 
schools  should  be  supplied  with  drawings,  representing  the  principal 
facts  in  the  science.  Also,  with  some  living  shells,  marine,  flu- 
viatile,  and  terrestrial ;  specimens  of  coral,  turf,  and  volcanic  pro- 
ducts, all  distinctly  labelled ;  these,  after  being  pointed  out,  should 
be  left  accessible  to  the  pupils. 

To  teach  them  the  composition  of  the  crust  of  the  earth,  there 
should  be  drawings  of  the  different  stratifications,  and  collections 
of  fossils  characteristic  of  the  several  formations,  all  distinctly 
labelled.  Where  fossils  cannot  be  obtained,  casts  representing 
them  will  serve  a  good  purpose.  Specimens  of  the  various  crys- 
talline and  sedimentary  rocks  should  form  a  part  of  the  teacher's 
apparatus. 

To  illustrate  the  various  effects  attributable  to  igneous  and 
aqueous  causes,  there  should  be  some  well-selected  specimens, 
distinctly  labelled,  of  fossil-shells,  encri'nites,  of  echini'deae,  of 
madrepores,  &c.,  in  order  to  compare  them  with  those  now  existing. 
Drawings  on  a  large  scale,  of  faults  and  crevices,  of  dykes  and 
injected  rocks,  of  basaltic  bosses  and  of  erosions  attributable  to 
water,  should  also  belong  to  the  school.  During  and  after  the 
lesson  referring  to  a  particular  part  of  the  subject,  these  speci- 
mens and  drawings  should  be  exhibited  and  explained  to  the  pupils. 


U.  S.  Naval  Hospital,         ? 
New  York,  October  16th,  1845.3 


CONTENTS. 


LESSON  I. 

GEOLOGY  DEFINED.  —  Form  of  the  Earth.  —  Its  Surface.  —  Internal  heat.  — 
Mineralogy  denned.  —  Definition  of  the  terra  Rock.  —  Formations. — 
Strata.— The  origin  of  Strata. — Vegetable  Earth.— Alluvium. — Divi- 
sion of  the  Formations. — Plutonic  formations. — Neptunian  or  Strati- 
fied Rocks.— Order  of  Strata. — Temple  of  Jupiter  Serapis.— Subsidence 
and  elevation  of  coasts  —  p.  11  to  20. 

LESSON  II. 

ORGANIC  REMAINS. — Fossils — how  produced. 

FIRST  GEOLOGICAL  EPOCH. — Primitive  Rocks. — Granite. — Gneiss.  —  Mica- 
Schist. — Argillaceous  Schist 

SECOND  GEOLOGICAL  EPOCH. — Transition  Formation. — Cambrian  System. — 
Silurian  System. — Trilobites  and  other  Animal  Remains. — Devonian 
System. — Fossil  Fishes. — Fossils. — Limits  of  the  Transition  Formation. 
— Strata  changed  in  position  by  Geological  Convulsions  —  p.  21  to  36. 

LESSON  III. 

THIRD  GEOLOGICAL  EPOCH. — Secondary  Formation. — Carboniferous  Forma- 
tion.—Old  Red  Sandstone.  —  Fossils.  —  Coal  Formation. — Fossils.— 
Extent  of  Coal  Measures. 

FOURTH  GEOLOGICAL  EPOCH.  —  New  Red  Sandstone.  —  Fossils.  —  Triassic 
System. — Bunter  Sandstein. — Muschelkalk. — Keuper. — Ammonites. — 
Fossils. 

FIFTH  GEOLOGICAL  EPOCH.  —  Lias  or  Liassic  System.  —  Fossils.  —  Ichthyo- 
saurus.— Pleisiosaurus.  —  Pteroda'ctylus. — Oolitic  System. — Fossils — 
p.  36  to  66. 

LESSON  IV. 

SECONDARY  FORMATION  continued. 

SIXTH  GEOLOGICAL  EPOCH. — Cretaceous  Formation. — Lower  Cretaceous  Sys- 
tem.— Fossils. — Wealden  Deposit.  —  Greensand.  —  Gault.  —  Fossils. — 
Upper  Cretaceous  System.— Fossils. — Extent  of  Cretaceous  Formation. 
— Table  of  Formations  —  p.  66  to  77. 

LESSON  V. 

SEVENTH  GEOLOGICAL  EPOCH. — Tertiary  Formation. — Eocene  Beds. — Paris 
Basin. — Fossils.  —  Anoplotherium. — Paleotherium.  —  Miocene  Beds. — 
Dinotherium — Lignites. — Pliocene  Beds — Fossils — Bone  caverns. 

SUPERFICIAL  DEPOSITS. — Drift. — Diluvium.  — Megatherium.  —  Boulder  For- 
mation.— Alluvium. — Big  Bone  Lick. 

EIGHTH  GEOLOGICAL  EPOCH. — Modern  Formation  —  p.  77  to  96. 

LESSON  VI. 

INFLUENCE  OF  INTERNAL  AGENTS  ON  THE  SURFACE  OF  THE  EARTH. 
EARTHQUAKES. — Description  of.  —  Effects  of.  —  Changes  of  level  produced 

by.  —  Upheaval  and  Subsidence. — Constant  level  of  Seas.  —  Slow  and 

Progressive  Subsidence. — General  Conclusion. 


X  GEOLOGY.  — CONTENTS. 

VOLCANIC  PHENOMENA. — Explosion. — Eruption. — Island  of  Saint  George.- — 
Monte-Nuovo. — Jorullo. — Vesuvius.  —  Definition  of  a  Volcano. — Sub- 
marine Eruptions. — Volcan  of  Unalaska. — Crater  of  Elevation. — For- 
mation ef  Craters. — Effects  of  Upheaval. — Form  of  Volcanic  Islands. — 
Periods  in  the  Formation  of  a  Volcano. — Interior  of  Craters. — Kirauea. — 
Solfataras. — Volcanic  Ashes. — Lava  Currents. — Characters  of  Lavas. — 
Dykes. — Gaseous  Volcanic  Products. — Eruption  of  Mud. — Solid  Pro- 
ducts of  Volcanoes. — Trachyte. — Obsidian. — Compact  Lavas. — Porous 
Lavas  —  p.  96  to  122. 

LESSON  VII. 

INFLUENCE  OF  EXTERNAL  AGENTS  ON  THE  SURFACE  OF  THE  EARTH.  —  Effects 
of  the  Atmosphere. — Degradation. — Effects  of  Winds. — Dunes. — Ef- 
fects of  Lightning. 

EFFECTS  OF  WATER. — Dissolving  Power. —  Softening  Power. — Denudation. — 
Erosion. — Effects  of  weight  of  Water. — Running  Waters. — Debacle 
of  Lakes. — Mud-Torrents.— Slope  of  Torrents  and  Rivers.— Rolled 
Flints. — Transportation  by  Ice  and  Glaciers. — Action  of  Waves. — De- 
posits formed  by  Water. — Geysers. — Structure  of  Sedimentary  Deposits. 
—Talus.— Effects  of  Transport  or  Drift.— Effects  of  Oscillation  in 
Waters. — Nature  of  Deposits  from  Water. — Coral  Reefs. — Polyparia. — 
Peat-Bogs  —  p.  122  to  144. 

LESSON  VIII. 

EXPLANATION  OF  VARIOUS  PHENOMENA. — Consequences  of  Central  Heat. — 
First  effect  of  Cooling. — Warm-Springs. — Deposits  referable  to  Sedi- 
ment.— Fresh  Water  Deposits. — Fossils  of. — Marine  Deposits. — Fossils 
of. — Carbonaceous  Deposits. 

EFFECTS  ATTRIBUTABLE  TO  UPHEAVAL  AND  SUBSIDENCE. — Shell  Deposits  and 
Raised  Beaches. — Submarine  Forests. — Tracks  of  Quadrupeds  and 
Birds. — Dislocation  of  Strata. — Faults. — Crateriform  arrangement  of 
Strata. — Valleys  of  Elevation. — Upheaval  without  Dislocation. — Dis- 
tortion of  Strata. — Origin  of  Valleys. — Valleys  from  Dislocation — from 
Subsidence — from  Folding  or  Plaiting — from  Erosion  or  Denudation. — 
Origin  of  Caverns  —  p.  144  to  166. 

LESSON  IX. 

EXPLANATION  OF  VARIOUS  PHENOMENA  CONTINUED. — Deposits  attributable  to 
Volcanic  Action.  —  Lava.  —  Basalt.  —  Action  of  Basalt  on  Adjacent 
Rocks. — Dolomisation. — Giants'  Causeway. — Trachytic  Formation. — 
Trap  Rocks. — Porphyry. — Granitic  Rocks. — Injection  of  Granite. — 
Metalliferous  Veins.--Metamorphism.--Effects  of  Erosion--p.  166  to  181. 

LESSON  X. 

CLASSIFICATION  OF  FORMATIONS. — Different  kinds  of  Stratification. — Dip.— 
Strike. — Conformable  Stratification. — Unconformable  Stratification. — 
False  Stratification.  —  The  form  and  habits  of  an  Animal  deducible 
from  a  single  bone. — Relative  ages  of  the  principal  catastrophes  of  the 
Globe. — Systems  of  Upheaval. — Classification  of. — State  of  Europe  at 
different  epochs  of  Formation.— Deluge — Geogeny  —  p.  181  to  210. 

GLOSSARY  — p.  211  to  235. 


OF  THE 

UNIVERSITY 


ELEMENftlJF  GEOLOGY. 


LESSON  I. 

GEOLOGY  DEFINED. —  Form  of  the  Earth  —  its  Surface — Internal 
Heat  —  Mineralogy  defined — Definition  of  the  term  Rock  — 
Formations — Strata — The  Origin  of  Strata —  Vegetable  Earth 
— Mluvium — Division  of  the  Formations — Plutonic  Forma- 
tions— Neptunian  or  stratified  Rocks — Order  of  Strata — Tem- 
ple of  Jupiter  Serapis — Subsidence  and  Elevation  of  Coasts. 

1.  GEO'LOGY  (from  the  Greek,  ge,  the  earth,  and  logos,  dis- 
course), or  science  of  the  earth,  is  that  branch  of  Natural  History 
which  treats  of  the  physical  constitution  of  our  globe. 

2.  The  earth,  as  is  generally  known,  is  in  form  of  a  ball,  or 
spheroid,  slightly  flattened  at  the  poles,  floating  freely  in  space. 
Its  diameter  is  about  8000  miles,  and  its  surface  is  irregular;  here 
it  is  studded  with  long  chains  of  mountains,  there  hollowed  by 
deep  depressions ;  but  these  inequalities,  however  gigantic  they 
may  appear,  when  compared  with  objects  surrounding  us,  are  in 
reality  very  trifling,  in  comparison  with  the  mass  of  the  globe  ; 
they  are  proportionally  much  less  than  those  we  see  on  the  skin 
of  the  smoothest  orange,  and  if  represented  on  a  ball  three  feet  in 
diameter,  the  highest  mountains  would  be  still  so  small  as  almost 
to  require  a  microscope  to  perceive  them. 

3.  The  deepest  excavations  of  the  surface  of  the  globe  are 
covered  by  great  masses  of  water  which  conceal  them  and  prevent 
their  examination ;  but  there  is  reason  to  believe  that  the  most  pro- 
found depressions  do  not  much  exceed  three  miles  in  depth,  below 
the  surface  of  the  sea,  and  we  know  by  exact  measurement  that 
the  summit  of  the  loftiest  mountains  is  not  six  miles  above  the 
same  level. 

Mont  Blanc,  the  highest  mountain  in  Europe,  is  15,748  feet;  Mont  Perdu, 
of  the  Pyrenees,  is  11,168  feet;  Peak  of  Teneriffe,  12,172  feet;  in  South 
America,  in  the  Cordillera  of  the  Andes,  there  are  still  higher  mountains ; 

1.  What  is  Geology  ? 

2.  What  is  the  form  of  the  earth ?     What  is  its  size?     What  is  the  cha- 
racter of  its  surface  ? 

3.  What  is  the  greatest  depth  of  the  sea  ?     What  is  the  greatest  height 
of  land  above  the  level  of  the  sea  ? 

(11) 


12         INTERNAL  HEAT  OF  THE  EARTH. 

Chimborazo,  21,440  ;  Illimani,  24,450  feet ;  and  Scrota,  25,000.  The  high- 
est mountain  in  the  world  is  in  Asia,  the  Himalaya,  which  rises  26,862  feet 
above  the  level  of  the  sea. 

4.  The  surface  of  the  earth  has  not  always  possessed  the  same 
configuration  that  it  now  presents  ;  it  has  been  frequently  upturned, 
and  there  is  even  reason  to  believe  that  the  entire  globe  was  a 
liquid  mass,  melted  by  heat,  and  that  it  gradually  became  solid  as 
it  cooled. 

5.  Except  at  comparatively  shallow  depths,  we  cannot  examine 
the  nature  of  the  materials  constituting  our  globe,  not  even  by 
descending  into  mines,  excavated  for  the  purpose  of  extracting  the 
wealth  they  contain ;  for  the  deepest  of  these  excavations  do  not 
exceed  500  yards.     But  by  calculations,  it  has  been  inferred  that 
the  centre  of  the  earth  cannot  be  occupied,  either  by  water,  or  by 
vapour,  but  by  matter  as  heavy  as  our  heaviest  metals,  and  so  hot 
that  it  is  probably  in  a  state  of  constant  fusion. 

6.  A  great  number  of  facts  concur  in  proving  that  the  earth 
possesses  an  internal  heat  (the  remnant  of  its  original  heat),  inde- 
pendent of  that  which  it  receives  from  the  sun.     Its  temperature 
increases   in   proportion  as  we   descend  to  considerable  depths ; 
there  are  some  very  deep  mines  in  which  the  workmen  can  only 
labour  when  naked,  and  wherever  the  water  of  a  spring  rises  from 
a  great  depth,  its  temperature  is  always  very  high.     This  increase 
of  temperature  has  even  been  measured,  and  it  has  been  ascer- 
tained that  the  heat  of  the  earth  increases  about  two  degrees,  Faren- 
heit,  for  every  70  to  100  feet.     In  very  deep  cellars,  where  the 
influence  of  the  seasons  is  not  felt,  and  where  the  temperature  is 
always  the  same,  the  thermometer,  at  Paris,  stands  at  about  51 
degrees,  and  at  a  depth  of  200  feet  below  these  cellars  the  heat  is 
about  55  degrees ;  at  a  league  below  the  surface,  the  temperature 
must  be  above  that  of  boiling  water,  and  at  a  depth  of  less  than 
two  leagues,  it  must  be  sufficient  to  melt  tin. 

7.  It  appears  to  be  demonstrated,  that  the  globe,  at  some  remote 
period,  was  in  a  state  of  incandescence,  or  liquefaction  from  heat, 
and  that  it  cooled  by  degrees ;  but  we  must  not  conclude  that  this 
cooling  process  has  continued  to  the  present  time,  and  is  still  going 
forward  ;  it  has  almost,  if  not  entirely,  ceased.     From  the  earliest 
records  of  history,  to  the  present  moment,  the  temperature  of  the 

4.  Has  the  surface  of  the  earth  always  been  the  same  in  form  and  shape 
as  it  now  is  ?     Is  it  supposed  that  the  globe  has  always  been  in  its  present 
condition  ? 

5.  What  occupies  the  centre  of  the  earth  ? 

6.  Is  the  temperature  of  the  earth  the  same  at  its  centre  as  it  is  on  the 
surface  ?     What  reasons  lead  us  to  the  conclusion  that  the  earth  possesses 
an  internal  heat? 

7.  Is  it  supposed  that  the  earth  is  becoming  cooler  and  cooler  every  day  ? 
How  is  the  earth  enabled  to  preserve  its  temperature  ? 


STRATIFICATION.  13 


globe  has  not  sensibly  changed,  and  by  the  calculations  of  the 
learned,  it  is  proved  that  the  surface  of  the  earth  receives  from  the 
sun  during  a  year  a  quantity  of  heat  equivalent  to  that  which  it 
loses  in  the  same  space  of  time ;  the  internal  heat  of  the  earth  no 
longer  influences  the  temperature  of  its  surface,  except  in  an  in- 
sensible degree,  and  to  diminish  this  influence,  which  is  almost 
none  at  all,  one-half,  would  require  the  lapse  of  30,000  years. 

8.  Our  knowledge  of  the  central  portion  of  the  globe  is  limited 
to  what  we  have  just  said  of  its  weight  and  temperature ;  but  the 
solid  crust,  constituting  its  surface,  has  been  better  studied. 

9.  This  crust  is  not  formed  of  a  single  piece,  but  is  composed 
of  a  great  number  of  various  materials.     The  study  of  these  vari- 
ous substances,  particularly,  belongs  to  Mineralogy  ;  the  study  of 
their  mutual  relations  and  the  more  or  less  important  part  they 
play  in  the  constitution  of  the  globe,  is  the  province  of  Geology. 

10.  In  general  we  give  the  name  of  rocks  to  mineral  substances, 
which  are  united  in  great  masses,  and  apply  the  term  formations, 
to  diverse  assemblages  of  rocks  which  appear  to  have  been  formed 
under  the  same  circumstances. 

The  word  rock,  as  used  by  geologists,  is  applicable  to  all  mineral  masses, 
whether  hard  or  soft,  and  therefore  includes  in  its  meaning,  sand,  marble, 
clay,  granite,  <fcc. 

11.  When  we  examine  the  sides  of  mountains,  artificial  exca- 
vations, and  various  other  localities  favourable  to  geological  studies, 
we  very  soon  perceive  there  are  a  great  many  different  formations, 
and  these  formations  are  in  layers  or  stories  reposing  one  above 
the  other,  constituting  strata:  (plural  of  stratum,  a  Latin  word, 
meaning  a  bed,  couch,  or  layer ;  anything  spread  out  or  strewed 
over  a  surface.) 

12.  We  can  be  convinced  of  this  by  examining  the  cuts  made 
through  hills  for  the  passage  of  rail-roads  and  canals  in  various 
parts  of  the  United  States.     By  comparing  the  different  materials 
composing  the  earth's  crust,  the  geologist  will  soon  be  satisfied  that 
these  different  rocks,  in  a  majority  of  instances,  are  not  placed  one 
alongside  the  other,  but  cover  each  other,  and  form  a  series  of 
layers,  of  more  or  less  thickness,  comparable  to  the  courses  or 
layers  in  a  mass  or  wall  of  mason-work.     Gypsum,  or  plaster  of 
paris,  for  example,  rests  upon  a  stratum  of  coarse  limestone,  for, 
in  digging  wells  in  the  neighbourhood  of  Paris,  at  different  points, 
the  coarse  limestone  is  always  found  below  the  plaster.     This 

8.  What  do  we  know  relative  to  the  centre  of  the  earth  ? 

9.  What  is  the  crust  of  the  earth  ?     Does  it  consist  of  one  piece  ?     What 
is  mineralogy  ? 

10.  What  are  rocks  ?     What  are  formations  ? 

11.  What  is  meant  by  stratum  ? 

12.  How  are  rocks  placed  relatively  to  each  other? 

2 


14  STRATIFICATION. 


coarse  limestone  in  its  turn  covers  a  stratum  of  plastic  clay ;  in 
many  places  where  the  coarse  limestone  is  not  very  thick,  it  has 
been  pierced  through,  and  the  plastic  clay  found  beneath  it. 

13.  But  it  is  not  necessary  to  dig  wells  in  order  to  be  certain  of 
the  superposition  of  the  different  layers  formed  by  these  rocks ;  it 
is  distinctly  seen  by  examination  of  the  declivities  of  certain  hills, 
or  cuts  made  through  them  for  the  passage  of  roads,  &c. ;  for, 
when  the  point  of  contact  of  two  layers  is  exposed  at  one  of  these 
localities,  we  may  frequently  distinguish,  without  difficulty,  the 
manner  in  which  one  of  these  layers  is  continued  beneath  the 
other. 

14.  In  other  places  nothing  similar  is  seen ;  the  rocks  show 
no  trace  of  stratification,  but  constitute  compact  masses,  such  as 
granite. 

To  form  an  idea  of  the  manner  in  which  nature  has  produced 
these  immense  earthy  layers,  we  must  study  the  phenomena  which 
are  now  taking  place  at  different  places  on  the  surface  of  the 
earth. 

15.  The  action  of  rain,  of  the  sun,  of  frost,  and  many  other 
causes  are  constantly  tending  to  change  the  surface  of  rocks,  even 
those  which  are  most  compact,  and  to  detach  fragments  from  them  ; 
these  fragments,  more  or  less  divided,  are  spread  out  over  the  sur- 
face of  the  soil,  mixed  with  the  detri'tus*  of  plants  and  animals, 
and  constitute  a  kind  of  movable  bed,  more  or  less  thin,  which 
covers  the  whole  surface  of  the  globe,  and  bears,  commonly,  the 
name  of  vegetable  earth,  because  it  is  in  this  bed  that  almost  all 
vegetables  grow.     The  mineral  substances  which  enter  into  its 
composition  are  ordinarily  sand,  clay,  or  the  debris,  or  remains  of 
calcareous  rocks. 

16.  When  currents  of  water  pass  over  movable  formations,  such 
as  we  have  just  mentioned,  they  take  up  a  portion  and  convey  to 
a  distance  the  detri'tus  and  debris  of  which  they  are  composed. 
In  this  way,  when  the  heaped-up  snows  on  the  tops  of  mountains 
melt  under  the  influence  of  the  summer's  sun,  or  when  abundant 
rains  fall  on  the  same  places,  impetuous  torrents  descend  towards 
the  plain,  and  carry  with  them  earth  and  fragments  of  stones  found 
in  their  route,  or  which  they  tear  up  from  their  resting-places ;  the 

*  DETRI'TUS. — A  geological  term  applied  to  deposits  composed  of  various 
substances  which  have  been  comminuted  by  attrition.  The  larger  frag- 
ments are  usually  termed  debris ;  those  which  are  pulverized,  as  it  were, 
constitute  detri'tus.  Sand  is  the  detri'tus  of  siliceous  rocks. 

13.  What  evidence  have  we  of  the  superposition  of  strata? 

14.  Are  all  rocks  stratified? 

15.  What  are  the  common  causes  which  tend  to  change  the  surface  of 
rocks  ?     What  is  detri'tus  ?     What  is  vegetable  earth  ?     What  is  debris  ? 

16.  How. do  currents  of  water  change  the  surface  of  the  earth? 


DEPOSITION  OF  SOIL  BY  RIVERS.  15 

result  is  that  the  water  of  these  torrents  is  often  turbid,  and  loaded 
with  mud,  sand,  flints,  or  even  blocks  of  stone ;  but  when  they 
reach  a  flat  country,  or  fall  into  a  large  basin,  their  course  is  much 
less  rapid,  and  the  foreign  materials  they  held  in  suspension  are 
gradually  deposited  ;  the  heaviest  sink  first,  and,  at  length,  these 
materials  line  the  bottom  of  the  river  with  an  earthy  bed,  whose 
thickness  is  continually  increasing. 

17.  The  river  Po,  which  is  precipitated  from  a  lofty  chain  of  the 
Alps,  and  traverses  Lombardy,  is  a  remarkable  example  of  this 
curious   phenomenon.     This  river,  and  its  principal   tributaries, 
have  transported,  in  this  way,  so  much  earthy  matter  from  the 
mountains  to  the  plain,  that,  since  the  Roman  era,  several  large 
lakes  and  extensive  marshes,  situated  near  Parma,  Paisance,  Cre- 
mona, &c.,  have  been  filled  up  and  become  dry :  the  bed  of  these 
rivers  is  also  gradually  filled  up,  so  that  they  have  several  times 
changed  their  course,  and  poured  over  the  neighbouring  plains. 
It  has  been  necessary  to  restrain  them  artificially,  by  building  up 
a  long  dyke  on  each  bank ;  this  has  put  an  end  to  these  disastrous 
inundations,  but  has  not  prevented  the  bottom  of  the  river  from 
continuing  to  rise  up ;  every  year  it  is  therefore  necessary  also  to  raise 
up  the  dykes,  so  that  now  these  rivers  flow  in  a  sort  of  immense 
aqueduct,  and  at  certain  places  the  surface  of  their  waters  is  higher 
than  the  roofs  of  the  surrounding  houses,  as  at  Ferrara,  for  ex- 
ample. 

18.  The  river  Rhone  descends  on  the  northern  side  of  the  Alps, 
and  passes  the  Valais  too  impetuously  to  deposit  the  mud  and  flints 
with  which  it  is  abundantly  freighted ;  but,  when  it  empties  into 
the  lake  of  Geneva^  its  course  becomes  so  slow  as  to  be  almost 
imperceptible,  and  its  waters,  which  were  at  first  turbid  and  muddy, 
are  limpid  and  transparent,  when  they  escape  from  the  opposite 
side  of  this  basin  to  pass  through  the  town  of  Geneva :  the  result 
is  that  the  Rhone  deposits  in  this  basin  all  the  matters  which  it 
carried,  and  gradually  raises  up  its  bottom,  constituting  what  is 
termed  lacustrine  formation.     This  progressive  elevation  of  the 
soil  is  so  marked  at  the  eastern  extremity  of  the  |^.ke,  that  an  an- 
cient town  called  Port  Valais,  formerly  situated  on  its  margin,  is 
now  found  about  a  half  a  league  from  it ;  about  eight  centuries 
have  been  sufficient  for  the  formation  of  the  great  earthy  bank 
which  now  separates  this  town  from  the  lake,  and  the  deposite 
which  gave  rise  to  it  continues  to  be  made  at  the  bottom  of  that 
portion  of  the  lake  in  its  vicinity,  and  continually  tends  to  raise  it 
up  more  and  more,  so  that  in  time  it  may  fill  the  whole  of  this 
basin,  and  transform  the  lake  into  a  plain  which  the  Rhone  will 
pass  through  without  spreading  itself.     In  passing  through  Geneva, 

17.  Give  an  example  of  change  produced  by  currents. 

18.  What  has  been  the  effect  of  the  Rhone  passing  through  the  lake  of 
Geneva  ?     What  is  meant  by  lacustrine  formation  ? 


16  ALLUVIUM — DELTAS. 


this  beautiful  river,  as  we  have  already  said,  is  clear  and  limpid  ; 
but  a  little  beyond  the  town  it  receives  new  tributaries,  such  as  the 
Arve,  which  pour  into  it  their  muddy  waters,  and  little  by  little  it 
is  again  loaded  with  sand  and  rnud,  which  it  rolls  on  impetuously 
to  the  sea ;  but  at  its  mouth,  its  course  being  slow,  these  foreign 
materials,  the  debris  of  Mont  Blanc,  of  the  Alps,  of  Dauphiny, 
and  the  central  regions  of  France,  are  in  their  turn  deposited,  and 
gradually  elevate  the  soil  they  cover ;  the  result  is  new  land  which 
advances  more  and  more  on  the  sea. 

19.  We  give  the  name  of  alluvium  (from  the  Latin,  alluvio,  an 
inundation,  or  alluo,  I  wash)  to  formations  caused  in  this  way  by 
the  deposite  of  materials  carried  by  waters,  and  as  these  alluvial 
formations,  when  deposited  at  the  mouth  of  a  river,  often  assume 
the  form  of  the  Greek  letter  A  delta,  we  designate  the  new-made 
land,  which  in  a  manner  encroaches  on  the  domain  of  the  sea, 
under  the  name  of  delta. 

20.  The  delta  of  the  Rhone,  to  which  we  alluded  above,  and 
that  which  is  found  at  the  mouth  of  the  Po,  are  very  inconsider- 
able ;  but,  in  certain  parts  of  the  globe,  several  are  found  of  very 
much  greater  geological  importance.     One  of  the  most  celebrated 
is  the  Delta  of  the  Nile,  which,  according  to  the  calculations  of 
some  authors,  must  have  grown  nearly  half  a  league  since  the 
time  of  Herodotus ;  and   according  to   the   commonly   received 
opinion,  its  formation  began  at  the  foot  of  the  rocks  upon  which- 
were  built  the  pyramids  of  Memphis ;  but  the  deltas  at  the  mouth 
of  the  Mississippi,  and  the  mouth  of  the  Ganges,  increase  more 
rapidly,  and  possess  greater  interest  for  the  naturalist. 

21.  Other  formations  are  also  produced,  so  to  speak,  under  our 
eyes,  by  the  deposite  of  materials  which  the  waters  of  certain 
springs  hold  in  solution,  and  throw  down  when  they  reach  the  sur- 
face of  the  earth.     In  different  parts  of  France,  near  a  spring 
situated  at  the  north  of  Clermont  Ferrand,  for  instance,  we  see 
examples  on  a  small  scale,  and  in  many  parts  of  Italy,  enormous 
masses  of  calcareous  stone,  known  under  the  name  of  Travertin 
(from  the  Italian,  travertine],  are  formed. 

22.  We  often  behold  issuing  from  the  craters  of  volcanoes,  a 
burning,  semi-liquid  matter,  which  spreads  over  the  surface  of  the 
neighbouring  country,  and,  on  cooling,  is  converted  into  a  hard 
compact  rock,  called  lava.     Etna  has  furnished  a  great  number  of 
irruptions  of  lava,  one  of  which  was  six  leagues  in  length,  and,  in 
1783,  Hecla,  a  volcano  of  Iceland,  gave  origin  to  a  similar  cur- 
rent, which  extended  twenty  leagues  in  length,  arid  twelve   in 
breadth. 

19.  What  is  alluvium  ?     What  is  a  Delta  ? 

20.  Mention  some  examples  of  Deltas. 
.  21.  What  is  Travertin  ? 

2ii,  What  is  lava  ? 


AQUEOUS  AND  PLUTONIC  FORMATIONS.  17 

23.  These  different  phenomena  partly  explain  to  us  the  manner 
in  which  the  production  of  the  different  formations  disseminated 
on  the  surface  of  the  globe,  must  have  been  effected,  formations 
whose  origin  date  back  from  an  epoch  long  anterior  to  that  of  the 
creation  of  man. 

24.  In  fact,  the  various  formations  constituting  the  common  por- 
tion of  the  globe  differ,  as  we  have  already  seen,  very  widely  in 
their  nature,  in  their  constitution,  and  in  their  mode  of  arrange- 
ment.    Now,  these  differences  remind  us  of  those  which  exist  in 
the  modern  formations  above  mentioned,  and  seem  to  indicate  that, 
in  the  ancient  formations,  some  were  produced  in  the  midst  of  the 
waters  by  the  deposit  of  solid  materials  held  in  suspension  or  in 
solution  by  this  liquid,  and  others  by  the  action  of  heat  on  earthy 
materials  susceptible  of  being  melted,  and  of  being   afterwards 
hardened  by  cooling. 

25.  Guided  by  these  considerations,  geologists  have  divided  the 
formations  into  two  great  classes ;   namely,  the  sedimentary,  or 
stratified  formations,  and  the  massif  or   igneous  formations. 
On  account  of  the  presumed  method  of  their  production,  they  are 
also  designated  under  the  names  of  Aqueous  or  Neptunian  for- 
mations, and  Igneous  or  Plutonic  formations. 

'  26.  The  plutonic  formations  have  received  this  name  because 
they  appear  to  be  the  product  of  the  action  of  fire ;  they  are 
generally  of  a  dense  crystalline  structure,  and  ordinarily  form  very 
immense  masses ;  they  are  not  arranged  in  regularly  superposed 
beds,  nor  do  they  contain  the  remains  of  organized  bodies.  Some 
of  them  are  formed,  as  we  see,  by  the  action  of  volcanoes,  and 
others  are  very  analogous  to  the  latter;  they  contain  not  only 
minerals  peculiar  to  volcanic  ejections,  but  sometimes  also  matters 
that  are  produced  by  the  furnaces  of  our  laboratories  and  Work- 
shops. They  seem  to  have  'formed  the  primitive  crust  of  the 
globe;  for  we  find  them  beneath  the  neptunian  formations,  but 
they  are  also  sometimes  spread  over  the  surface  of  the  latter,  or 
betwixt  the  different  beds  or  strata  of  which  they  are  composed. 

27.  The  aqueous  or  neptunian  formations  appear  to  have  been 
deposited  by  the  waters ;  in  general  their  texture  is  coarse  or  com- 
pact, rarely  crystalline,  and  they  are  often  composed  of  grains  of 
sand  separate  or  agglutinated,  of  heterogenous  fragments,  or  ma- 
terial having  the  aspect  of  a  kind  of  indurated  mud ;  they  are  also 
frequently  called  stratified  formations,  and  most  of  them  are  also 
termed  SEDIMENTARY  FORMATIONS.  It  is  in  the  midst  of  these  for- 

23.  Are  the  various  formations  all  of  the  same  age  ? 

24.  In  what  manner  were  the  various  formations  produced  ? 

25.  How  are  the  formations  divided  ? 

26.  What  is  meant  by  plutonic  formations  ?     How  are  they  produced  ? 

27.  How  were  the  aqueous  formations  produced  ?     What  are  the  charac- 
ters of  aqueous  rocks  ? 

2* 


18  ORDER  OF  STRATA. 

mations  that  we  find  the  remains  of  the  different  organized  bodies 
by  which  the  earth  has  been  successively  peopled. 

28.  These  stratified  formations  were  not  all  produced  at  once, 
but  successively,  and  under  the  influence  of  different  circumstances ; 
they  constitute,  as  we  have  before  said,  distinct  beds  or  strata, 
and  these  strata  lie  one  on  top  of  the  other,  so  that  those  of  a  more 
ancient  are  found  beneath  those  of  a  more  recent  formation.     By 
studying  them  carefully  we  shall  also  perceive  that  different  points 
on  the  surface  of  the  earth  have  been  successively,  and  at  intervals, 
left  dry,  and  covered  by  the  waters  of  the  sea,  or  by  fresh  water, 
the  sediment  from  which  constitutes  these  banks,  and  we  see  that 
these  banks  themselves  differ,  not  only  in  the  nature  and  disposi- 
tion of  their  constituting  elements,  but  also  in  the  nature  of  the 
remains  of  the  organic  bodies  buried  in  their  substance. 

29.  We  distinguish  a  great  number  of  these  stratified  forma- 
tions, and,  as  might  be  anticipated  from  their  mode  of  production, 
they  are  everywhere  found  in  the  same  order  of  superposition  ; 
the  formation  which,  in  one  locality,  covers  another  formation,  can 
never  be  found  in  another  place  beneath  the  latter;  it  may  be 
entirely  wanting,  so  as  to  leave  the  latter  uncovered,  or  in  contact 
with  a  stratum,  which  in  another  place  it  covered  ;  but  wherever 
it  exists,  it  must  be  on  top  of  or  superior  to  all  formations,  the  pro- 
duction of  which  dates  back  to  a  more  remote  epoch. 

30.  For  example,  we  have  stated  that  in -the  vicinity  of  Paris,  the 
gypsum  rests  upon  the  coarse  limestone,  this  upon  the  plastic  clay, 
and  this  plastic  clay  upon  the  chalk;  in  other  localities  we  may 
find  new  strata  interposed  between  these  various  formations,  or  we 
may  find  one  of  them  entirely  wanting ;  for  example,  the  plastic 
clay  being  absent,  the  coarse  limestone  would  be  found  resting 
directly  upon  the  chalk;  but  this  coarse 'limestone,  for  the  reason 
alone  that  it  is  everywhere  found  resting  upon  the  chalk,  must  have 
been  deposited  after  the  chalk  was  formed,  and  consequently  can 
never  be  found  below  it. 

31.  It  is  also  evident  that  when  these  solid  beds  are  slowly 


Sea. 


Sedimentary  Rocks. 
Plutonic  Rocks. 
Fig.  1. 


28.  Were  the  stratified  formations  all  produced  at  the  same  time  ?     Are 
all  the  stratified  rocks  alike  in  character  ? 

29.  Are  the  stratified  formations  always  found  in  the  same  order  of  suc- 
cession ?     Are  all  the  strata  everywhere  found  ? 

30.  Give  an  example  to  show  that  the  strata  are  always  found  in  the  sama 
order  of  succession. 

31.  What  is  the  position  of  sedimentary  rocks  ? 


MOVEMENTS  OF  STRATA.  19 

deposited  at  the  bottom  of  waters,  they  must  have  a  nearly  hori- 
zontal position  (Jig.  1),  and  that  they  must  occupy  the  steepest 
parts  of  the  surface  upon  which  they  are  formed,  so  that  if  the 
surface  presents  considerable  elevations,  these  may  remain  un- 
covered, and  show  themselves  above  the  level  occupied  by  the 
new  formation  (Jig.  2).  Thus  when  we  go  from  low  plains 


Fig.  2. 

towards  mountain  chains,  and  ascend  to  their  summits,  we  meet, 
successively,  formations  more  and  more  ancient  as  we  rise. 

32.  Sometimes  these  stratified    rocks   preserve  the  horizontal 
position  they  had  in  the  beginning ;  but  at  other  times  they  become 
more  or  less  oblique  in  consequence  of  their  partial  depression  or 
sinking,  or  their  unequal  elevation.     Frequently  we   see   beds 
which  are  abruptly  raised  up,  so  as  to  be  almost  perpendicular ; 
and  on  the  edges  of  the  elevation  produced  by  this  overturning  of 
nature,  we  find  other  beds  which  are  perfectly  horizontal,  and  we 
may  conclude  that  the  latter  were  formed  subsequently  to  the  ele- 
vation of  the  former ;  by  studying  these  relations  of  position  we 
are  enabled  to  determine  the  geological  age  of  mountains. 

33.  These  great  movements  of  strata  sometimes  take  place  sud- 
denly, and  are  accompanied  by  earthquakes ;  but  at  other  times 
they  are  effected  gradually  and  without  any  shock.     It  appears  to 
be  well  ascertained  that  since  the  time  of  the  Romans,  a  portion 
of  the  coast  of  Naples  sank  below  the  level  of  the  sea,  and  was 
subsequently  raised  up  again  above  this  level,  without  overturning 
the  monuments  built  on  this  movable  soil.     One  may  be  satisfied 
of  this  fact  by  visiting  an  ancient  temple  situated  near  Puzzuoli, 
called  the  Temple  of  Jupiter  Serapis ;  this  monument,  of  which 
three  columns  remain  standing  erect,  appears  to  have  been  built  in 
the  third  century,  and  was  then  very  much  frequented,  on  account 
of  its  warm  baths  ;  but  at  a  subsequent  epoch,  supposed  to  be  about 
1488,  the  ground  sank  down,  and  the  temple  was  covered  by  the 

32.  Do  stratified  rocks  always  preserve  their  original  position  ?     What  is 
to  be  learned  by  studying  the  position  of  strata  ? 

33.  How  do  these  great  movements  of  strata  take  place  ?     Give  an  in- 
stance  of  the  gradual  movement  of  strata. 


20 


ELEVATION  OF  COASTS. 


Fig.  3. —  Temple  of  Serapis. 


sea  to  a  height  of  about  six- 
teen feet  above  the  pavement. 
Marine  animals  then  establish- 
ed themselves  on  a  portion  of 
the  submerged  columns,  and 
mollusks  of  the  genus  Pholas 
excavated  innumerable  holes 
in  the  same  way  as  they  do 
rocks  now  covered  by  the  sea ; 
but  in  the  present  day  the  state 
of  things  is  not  the  same,  the 
pavement  of  the  temple  is  again 
dry,  and  the  traces  of  the  pho- 
lades  we  have  just  mentioned 
are  at  a  considerable  height 
above  the  level  of  the  sea  (Jig. 
3).  Now,  these  changes  in  the 
relative -levels  of  the  coast  of 
Puzzuoli,  and  the  neighbour- 
ing sea,  cannot  be  attributed 
to  an  alternate  sinking  and  rise 
of  the  waters,  because  move- 
ments of  this  sort  must  have  been  accompanied  by  fearful  inun- 
dations along  the  shores  of  the  Mediterranean,  and  we  cannot  ex- 
plain this  phenomenon  except  by  supposing  that  the  coast  itself, 
after  sinking,  was  again  gradually  raised  up. 

34.  At  the  present  time  Scandinavia  and  Chile  exhibit  an 
analogous  phenomenon.  On  the  coasts  of  Sweden,  for  example, 
we  see  certain  rocks,  which  were  formerly  submerged,  now  above 
water,  and  that  the  steep  shore  is  gradually  rising  more  and  more 
above  the  level  of  the  sea.  For  a  long  time  it  was  observed  that 
the  sea  abandoned  certain  parts  of  the  coast,  and  that  the  depth  of 
water  decreased  in  several  ports  of  this  region  ;  but  these  changes 
of  level  have  been  ascertained  in  a  more  exact  manner;  more  than 
a  century  since,  marks  were  made  on  different  rocks  on  a  line  with 
the  surface  of  the  water,  to  serve  as  points  of  comparison,  and  on 
examining  them  from  year  to  year,  it  was  found  that  these  marks 
were  successively  higher  and  higher  above  the  level  of  the  sea. 
In  the  gulf  of  Bothnia,  this  rise  appeared  to  be  four  feet  in  a 
century,  but  at  other  places  less,  and  at  some  points  on  the  coasts 
of  the  Baltic,  it  was  nothing,  which  proves  that  the  change  of  level 
does  not  depend  on  the  subsidence  of  the  sea. 

We  shall  recur  to  the  subject  of  stratification  and  the  various 
causes  which  influence  it,  after  we  have  studied  the  characters  of 
the  various  formations. 


34.  What  other  instances  prove  the  slow  movement  of  strata  ? 


ORGANIC  REMAINS.  21 


LESSON  II. 

ORGANIC  REMAINS. — Fossils — How  produced. 

FIRST  GEOLOGICAL  EPOCH. — Primitive  Rocks — Granite — Gneiss 
— Mica-  Schist — Argillaceous-  Schist. 

SECOND  GEOLOGICAL  EPOCH. — Transition  Formation — Cambrian 
System — Silurian  System — Trilobites  and  other  animal 
remains — Devonian  System — Fossil  Fishes — Fossils — Limits 
of  the  Transition  Formation  — Strata  changed  in  Position  by 
geological  Convulsions. 

1.  We  find  entombed  in  the  different  strata  of  the  crust  of  the 
globe  a  great  quantity  of  the  remains  of  organic  bodies,  which  at 
different  epochs  have  lived  on  its  surface.     Those  which  exist  in 
the  present  formations,  and  which  have  been  deposited  since  the 
last  great  revolutions  of  the  earth,  generally  preserve  their  primi- 
tive composition ;  but  those  which  have  been  found  in  the  more 
ancient  strata  have  be^i  altered  in  their  nature,  and  passed  into 
the  fossil  state;  the  gelatinous,  fleshy,  or  ligneous  portions,  which 
concurred  in  their  formation,  have  in  part  disappeared,  and  have 
been  more  or  less  replaced  by  stony  particles.     By  the  term  fossil 
(formed  from  the  Latin,  fodio,  I  dig)  is  meant  any  organic  body, 
or  the  traces  of  any  organic  body,  whether  animal  or  vegetable, 
which  has  been  buried  in  the  earth  by  natural  causes. 

2.  Tn  general,  it  is  the  hard  parts,  those  that  are  capable  of  long 
resisting  decomposition,  which  alone  undergo  this  kind  of  altera- 
tion ;  such  as  bones,  shells,  and  scales,  for  example.     We  never 
find  flesh,  nor  nails,  nor  soft  fruits,  nor  other  analogous  bodies,  in  a 
fossil  state.     Sometimes  even  these  hard  bodies  disappear,  and 
leave  merely  traces  of  their  existence  in  an  impression  or  print  in 
the  rock  that  enveloped  them. 

3.  The  organic  remains  which  are  found  in  the  most  superficial 
and  most  recent  strata  of  the  crust  of  the  earth,  belong  in  part  to 
species  which  still  exist;  but  most  fossils  are  derived  from  ani- 
mals or  plants  which  have  not  existed  since  a  period  anterior  to 

1.  In  what  respects  do  the  organic  remains  found  in  the  most  ancient 
formations  differ  from  those  found  in  the  more  modern  strata  ?     What  is 
meant  by  the  term  fossil  ? 

2.  What  parts  of  organized  bodies  are  found  in  the  fossil  state  ? 

3.  Are  the  animals  and  plants  found  in  the  fossil  state  the  same  as  those 
now  existing  on  the  face  of  the  earth  ?     Are  all  the  varieties  of  fossils  dis- 
tributed through  the  divers  strata  without  regard  to  the  age  of  the  forma- 
tions ? 


22  REVOLUTIONS  OF  THE  EARTH. 

historic  times,  and  the  species  of  which  are  now  totally  extinct. 
In  general,  they  differ  from  species  now  living,  more  and  more,  in 
proportion  to  the  antiquity  of  the  strata  in  which  they  are  found, 
and,  in  most  of  the  strata  of  the  earth's  crust  we  find  certain 
species  which  are  not  met  with  either  in  more  ancient  or  more 
recent  formations. 

4.  It  is  by  comparing  the  fossils  with  each  other,  and  by  com- 
bining this  study  with  that  of  the  order  of  superposition,  in  which 
the  different  strata  are  found,  and  with  their  mode  of  formation, 
that  we  have  arrived  at  a  knowledge  of  the  earth  at  periods  long 
anterior  to  the  creation  of  man,  and  are  enabled  to  trace  the  his- 
tory of  the  great  revolutions  which  have  successively  disturbed 
and  changed  its  surface. 

5.  We  learn  by  this  study  that  the  physical  condition  of  the 
surface  of  the  earth,  as  well  as  that  of  the  organized  beings  by 
which  this  surface  is  inhabited,  has  undergone  great  and  nume- 
rous changes.     Entire  creations  of  animals  and  of  plants  have  suc- 
ceeded each  other ;  after  having  peopled  the  waters  and  inhabited 
the  land  for  ages,  each  in  its  turn  has  been  destroyed  by  some 
great  catastrophe  of  nature,  and  given  place  to  a  new  creation. 
But  the  appearance  of  a  new  flora,  or  a  new  fauna,  the  destruction 
of  living  beings,  and  the  deposit  of  enormous  beds  of  rocks,  are 
not  the  only  phenomena  which  characterifb  the  great  revolutions 
of  the  earth.     At  different  epochs,  total  overthrows,  of  which  the 
most  fearful  earthquakes  and  volcanic  eruptions  of  our  times  can 
give  but  a  very  feeble  idea,  have  raised  up  the  solid  crust  of  the 
globe,  and  produced  lofty  chains  of  mountains,  whose  elevation, 
immense  as  it  appears  to  us,  was  even  still  greater  before  the  val- 
leys and  basins  that  separate  them  were  gradually  filled  by  new 
deposits. 

6.  The  great  revolutions  of  the  earth  appear  to  have  been  sepa- 
rated by  long  periods  of  tranquillity,  during  which  animals  and 
plants  multiplied  on  different  parts  of  the  globe's  surface,  and  de- 
posits of  solid  materials,  borne  by  the  waters  or  drawn  from  the 
bosom  of  the  earth,  were  heaped  up,  constituting  beds  of  rocks  of 
greater  or  less  thickness,  and  varying  in  their  nature,  in  the  sub- 
stance of  which  were  entombed  the  remains  of  contemporaneous 
animals  and  plants. 

7.  The  natural  history  of  the  globe  is  written  in  the  very  rocks 
of  which  our  planet  is  composed,  and  the  study  of  these  ancient 
monuments  of  the  power  of  the  CREATOR  teaches  us  what  tran- 
spired long  before  the  existence  of  man  on  the  earth.     These  fos- 

4.  By  what  means  do  we  study  the  geological  history  of  the  earth? 

5.  What  are  the  great  facts  taught  by  the  study  of  geology  ? 

6.  What  seems  to  have  occurred  in  the  long  intervals  of  tranquillity 
between  the  great  geological  revolutions  of  the  earth  ? 

7.  Does  geology  teach  us  that  the  earth  was  always  inhabited  by  man  ? 


NATURAL  REVOLUTIONS.  23 

sils  are  truly  the  medals  of  creation,  medals  which  are  more  im- 
portant and  incomparably  more  ancient  than  all  those  of  Greece 
and  Rome,  or  the  hieroglyphics  of  Egypt. 

OF  THE  NATURAL  REVOLUTIONS  OF  THE  GLOBE. 

8.  The  history  of  the  globe,  like  that  of  nations,  is  divided  into 
a  certain  number  of  distinct  periods.,  during  each  of  which  the 
state  of  things  changed  but  little,  yet  it  resembles  neither  that 
which  preceded  nor  that  which  followed  after  it. 

9.  Geologists  designate  under  the  term  formation,  the  assem- 
blage of  rocks  which  were  produced  during  each  one  of  these 
periods  comprised  in  the  interval  between  two  of  these  revolu- 
tionary disturbances  of  the  globe. 

10.  For  example,  they  give  the  name  of  creta'ceous  formation 
(from  the  Latin,  creta,  chalk)  to  the  assemblage  of  rocks  which 
were  deposited  or  derived  from  the  interior  of  the  earth,  during  a 
geological  epoch,  in  a  part  of  which  chalk  was  deposited ;  and 
juras'sic  formation  is  the  name  given  to  the  assemblage  of  con- 
temporaneous sedimentary  rocks  composing  the  most  remarkable 
strata  of  the  mountains  of  Jura,  &c. 

Beginning  with  the  most  ancient,  we  will  examine  these  several 
formations  in  succession. 


FIRST  GEOLOGICAL  EPOCH. 

Primitive,  Primary,  Primordeal,  or  Unstratified  Roclcs.* 

11.  Under  the  name  of  primitive,  or  primary  rocks  (from  the 
Latin,  primus,  first,  before),  we  ordinarily  designate  the  different 
rocks  which  appear  to  have  been  formed  before  the  creation  of 
plants  and  animals,  the  remains  of  which  are  found  in  less  ancient 
strata,  and  seem  to  be  a  foundation  for  rocks  subsequently  pro- 
duced. 

*  Mr.  Lyell  proposes  to  designate  this  system  of  rocks  by  the  term 
Hypo'gene  (from  the  Greek,  vpo,  under,  and  geinomai,  I  beget),  because 
they  are  found  under  other  rocks.  He  objects  to  the  words  primary  and 
primitive,  because  these  terms  convey  a  notion  as  to  the  time,  and  age  of 
the  formation,  and  might  lead  to  the  error  of  supposing  that  they  were 
formed  before  any  other  rocks  were  formed,  but  the  term  hypo' gene  refers 
exclusively  to  position. 

&.  How  is  geological  history  divided  ? 
9.  What  is  meant  by  the  term  formation  ? 

10.  What  is  meant  by  creta'ceous  formation?     What  is  meant  by  juras'- 
sic formation  ? 

11.  What  is  meant  by  primitive  or  primary  rocks? 


24  FIRST  GEOLOGICAL  EPOCH.— GRANITE. 

12.  As  already  stated,  at  its  origin  our  globe  must  have  been  a 
mass  kept  in  a  state  of  fusion  by  the  action  of  heat,  and  its  surface 
became  solid  by  slowly  cooling.     This  first  crust  must  have  re- 
mained for  a  long  time  in  a  soft  or  pasty  condition,  and  at  first  its 
temperature  must  have  been  too  high  to  permit  water  to  remain 
on  its  surface  without  evaporating.     It  must  have  been  split  in 
different  directions  by  the  contraction  produced  by  cooling,  and 
then  resembled  the  masses  of  ice  which  in  our  day  cover  the  sur- 
face of  the  polar  seas ;  that  is,  it  presented  a  very  unequal  surface, 
studded  with  immense  fragments  heaped  up  in  all  directions.     In. 
this  first  geological  epoch  were  formed  the  massive  rocks,  such  as 
granite,  which  serves  as  the  base  of  all  other  rocks,  and  is  the 
result  of  the  solidification  of  mineral  substances  previously  melted 
by  heat.     The  cooling  of  this  first  crust  must  have  also  caused 
the  precipitation  of  the  least  volatile  matters  diffused  in  the  atmo- 
sphere, just  in  the  same  manner  as  a  cold  body  placed  in  a  warm 
moist  air  is  quickly  covered  by  a  layer  of  condensed  vapour ;  and 
from  this  cause  came  new  changes  in  the  configuration  of  the  sur- 
face of  the  globe,  and  the  formation  of  new  beds  of  a  crystalline 
texture. 

13.  The  most  ancient  portion  of  the  crust  of  the  earth  known 
to  geologists  is  composed  chiefly  of  granite  and  some  other  un- 
stratified  rocks  which  appear  to  be  also  of  igneous  origin. 

14.  We  give  the  name  of  granite  to  a  rock,  which  is  extremely 
hard,  having  a  rough  fracture,  which  is  composed  of  a  confused 
agglomeration  of  crystals  formed  of  three  distinct  materials :  some 
of  these  crystals  have  a  glassy  appearance,  and  are  ordinarily  of 
a  grayish  colour ;  they  are  quartz,  the  same  material  of  which 
rock  crystal  is  composed ;  others,  often  large,  opaque,  and  some- 
times rose-coloured,  sometimes  green,  sometimes  white  or  yellow, 
are  formed  of  a  mineral  catted  f eldspar ;  and  the  third  variety  of 
crystals,  which  are  composed  of  mica,  resemble  small  brilliant 
spangles,  sometimes  black,  and  sometimes  silvery  white.     Granite 
then  consists  of  quartz,  feldspar,  and  mica.     Certain  varieties  of 
granite  remain  for  centuries  exposed  to  the  inclemencies  of  the 
weather  without  undergoing  any  alteration  ;  but  other  varieties  are 
speedily  disintegrated  by  the  action  of  the  atmosphere,  and  are  thus 
reduced  to  a  kind  of  grit  or  argilla'ceous  earth.     It  presents  no 
trace  of  stratification,  and  possesses  all  the  characters  of  a  rock  of 
igneous  origin. 

12.  What  is  supposed  to  have  been  the  condition  of  the  earth  when  first 
formed?     What  was  the  condition  of  the  crust  of  the   earth  when  first 
formed  ?     Was  it  smooth  and  regular  ? 

13.  Of  what  is  the  most  ancient  portion  of  the  crust  of  the  earth  com- 
posed  ? 

14.  What  is  granite?     Of  what  minerals  is  it  composed  ?     What  is  the 
character  of  granite  for  durability  ? 


GNEISS,  MICA-SCHIST,  &c.  25 

15.  Granite,  which  seems  to  form  the  first  basis,  the  foundation 
stone  of  the  great  geological  edifice,  remains  uncovered  at  various 
points  on  the  surface  of  the  earth,  while  in  other  places  it  is 
covered  by  more  or  less  numerous  beds  of  more  recent  formations. 
But  all  the  granitic  rocks  now  scattered  over  the  surface  of  the 
globe  do  not  date  from  an  antiquity  so  remote ;  for,  in  different 
recent  epochs,  mineral  materials  in  a  state  of  fusion  have  escaped 
from  the  bosom  of  the  earth,  which  spread  over  formations  then 
existing,  and,  on  cooling,  constituted  immense  masses  of  granite 
similar  to  that  first  formed. 

16.  This  rock  is  met  with  in  different  places  in  all  parts  of  the 
xvorld,  and  is  employed  in  the  construction  of  edifices  of  various 
description. 

17.  The  beds  which  are  deposited  on  the  first  massive  crust  of 
the  globe  are  crystalline  in  structure,  and  this  character  is  more 
decided  the  more  ancient  they  are ;  they  seem  to  have  been  ex- 
posed to  the  action  of  a  great  heat,  without  possessing  the  charac- 
ters of  rocks  of  igneous  origin.     They  consist  principally  of  gneiss, 
mica-schist,  and  argillaceous  schist. 

IS,  Gneiss  is  a  rock  very  analogous  to  granite  as  respects  its 
elementary  constituents,  but  its  structure  is  foliated  and  presents  a 
stratified  arrangement ;  it  appears  to  have  been  formed  under  wa- 
ter, and  seems  to  be  the  most  ancient  of  the  sedimentary  forma- 
tions, because  in  certain  places  on  the  surface  of  the  globe  we  find 
it  covered  by  all  the  other  formations.  We  often  see  it  naked ;  it 
forms  vast  systems  of  rocks  in  which  it  is  often  alternated  with 
mica-schist  and  other  ancient  rocks.  It  is  used  in  building  and 


flagging. 
19.  Mi 


19.  Mica-schist  is  a  lamellar  rock  composed  of  quartz  ordinarily 
grayish,  and  a  great  quantity  of  brilliant  lamellae  of  mica  arranged 
in  extended  leaves  or  scales ;  it  commonly  accompanies  granite  and 
gneiss. 

20.  Argillaceous  schist  is  in  appearance  an  earthy  rock,  which 
is  easily  divided  into  large  laminae  more  or  less  thin,  and  was  evi- 
dently formed  under  water  by  the  deposit  of  sediment.     [Schist, 
from  the  Greek  schistos,  slaty,  easily  split.] 

We  also  find  in  these  primitive  strata  compact  limestone  of  great 
hardness,  and  other  rocks  which  more  or  less  resemble  the  pre- 
ceding. . 

21.  These  different  rocks,  the  origin  of  which  dates  from  the 

15.  Is  granite  everywhere  hid  beneath  the  surface  of  the  earth?     Is  all 
granite  supposed  to  be  of  the  same  age  ? 

16.  Where  is  granite  found  ?     To  what  uses  is  it  applied  ? 

17.  What  kind  of  rocks  are  found  overlying  the  granite? 

18.  What  is  gneiss ?     How  does  it  seem  to  have  been  formed? 

19.  What  are  the  characters  of  mica-schist  ? 
20    What  is  argilla'ceous  schist  ? 

3 


26          SECOND  GEOLOGICAL  EPOCH. 

earliest  period  of  geological  history,  constitute  a  great  part  of  the 
present  surface  of  the  globe,  and  are  often  found  at  great  depths, 
beneath  less  ancient  formations.  They  present  evident  traces  of 
great  overthrows,  and  the  beds  or  layers  which  they  form  no  longer 
occupy  the  horizontal  position  they  must  have  had  in  the  begin- 
ning, but  are  more  or  less  inclined,  twisted  and  fractured,  as  if  at 
various  times  they  had  been  broken  and  their  immense  fragments 
irregularly  raised  up.  Those  countries  in  which  the  primitive 
rocks  constitute  the  surface  are  knotted  and  mountainous,  and  we 
find  these  same  rocks  in  the  most  elevated  points  of  the  globe, 
where  they  form  the  mass  of  most  great  mountain  chains. 

22.  The  central  plane  of  France,  comprising  Auvergne,  Limou- 
sin, Vivarais,  and  Valais,  is  formed  almost  entirely  of  primitive 
rocks,  most  of  which  are  granitic.     The  same  is  true  of  a  great 
part  of  Brittany  and  Corsica,  Scandinavia  and  Finknd,  &c. ;  these 
ancient  rocks  also  constitute  a  krge  part  of  the  Great  Alps,  of 
which  Mont  Blanc  is  the  highest  point,  the  Eastern  Alps  from 
Saint  Gothard  to  Hungary,  the  Pyrenees,  the  chain  of  Erzge- 
berge,  in  Saxony,  the  Grampian  Hills  of  Scotland,  the  Oural 
mountains,  in  Russia,  the  Alleghanies  in  the  United  States,  and 
the  Andes  in  South  America. 

23.  As  we  have  already  stated,  we  find  no  fossils  in  the  sedi- 
mentary formations  of  this  geological  period,  and  it  is  therefore 
inferred  that  in  this  epoch  no  living  beings  existed  on  the  surface 
of  the  globe  ;  but  it  may  have  been  otherwise,  and  the  absence  of 
fossils  in  these  strata  depends  on  some  cause,  such  as  their  destruc- 
tion by  heat,  resulting  from  their  vicinity  to  enormous  masses  of 
igneous  rocks,  effused  near  to,  or  even  over  and  above  these  non- 
fossiliferous  strata. 

SECOND  GEOLOGICAL  EPOCH. 
Transition  Formation. 

24.  The  stratified  formations  which  rest  on  the  primitive  strata 
just  mentioned,  present  us  with  the  first  traces  of  the  existence  of 
living  beings  on  the  surface  of  the  globe,  and  constitute  a  particular 
division,  generally  named  the  Transition  Formation,  but  desig- 
nated by  Mr.  Lyell  as  the  Primary  Fossiliferous  Formation.    The 
most  recent  name  given,  however,  to  these  formations,  is  palaeozoic 
(formed  from  the  Greek  poluios,  ancient,  and  zbon,  an  animal),  be- 
cause they  contain  ancient  animal  remains. 

21.  Are  primitive  rocks  found  only  beneath  the  more  recent  formations? 

22.  In  what  countries  do  we  find  primitive  rocks  at  the  surface  ? 

23.  What  fossils  are  found  in  the  primitive  sedimentary  rocks  ? 

24.  In  what  formations  are  fossils  first  met  with  ?     What  is  meant  by 
palaB'ozoic  formation  ? 


CAMBRIAN  SYSTEM.  27 

25.  These  formations  closely  resemble  the  preceding,  and  it  is 
often  difficult  to  distinguish  them,  but  they  do  not  appear  to  nave 
begun  to  form  until  the  first  had  been  disturbed  by  some  great 
geological  convulsion ;  for  the  strata  of  which  they  are  composed 
are  not  parallel  to  those  of  the  rocks  on  which  they  rest,  and  they 
differ  from  them  by  having  fossils  entombed  in  their  substance. 
They  appear  to  have  been  formed   by  a  slow  and  continuous 
deposit  of  sand,  mud,  and  other  materials  suspended  in  water, 
and  they  consist  chiefly  of  schists  and  calcareous  rocks.     The  sea 
seems  then  to  have  covered  the  greatest  part  of  the  known  surface 
of  the  globe,  for  we  scarcely  find  a  trace  of  terrestrial  plants,  and 
immense  depots  of  these  strata,  almost  identical  in  character,  are 
met  with  in  the  most  distant  parts  of  the  earth,  as  in  Germany, 
England,  and  America. 

26.  To  judge  by  the  fossils  concealed  in  these  formations,  the 
globe  was  then  inhabited  by  a  small  number  of  plants,  belonging, 
for  the  most  part,  to  the  family  of  fucus,  and  by  a  multitude  of 
marine  animals,  the  forms  of  which  differed  widely  from  those  now 
existing.     It  is  also  remarked  that  most  of  these  animals  belonged 
to  the  inferior  classes  of  the  animal  kingdom,  and,  until  lately,  it 
was  believed  no  vertebrate  animal  then  existed ;  but  within  a  short 
time  it  has  been  ascertained  there  were  marine  fishes,  for  remains 
of  them  have  been  discovered  in  certain  rocks  whose  formation 
dates  back  to  this  remote  epoch.     (Fig.  20.) 

27.  The  most  ancient  beds  of  the  transition  formation  contain 
very  few  fossils,  while*  other  rocks  of  the  same  formation  are  rich 
in  these  remains  ;  these  differences,  which  correspond  with  other 
peculiarities  of  stratification,  have  led  geologists  to  divide  this  period 
into  three  divisions,  called  the  CAMBRIAN,  SILURIAN,  and  DEVONIAN 
Systems  of  rocks. 

28.  The  CAMBRIAN  (from  Cambria,  in  Wales)  or  SCHISTOSE  SYS- 
TEM.    The  Cambrian  rocks  are  the  lowest  sedimentary  deposits 
known.     They  are  composed  essentially  of  schistose  grauwackes, 
which  pass  through  all  shades  of  solidity,  lustre  and  colour ;  on 
one  side  they  unite  with  the  mica-schists  and  gneiss,  and  on  the 
other  with  the  coarse  grauwackes,  with  which  they  are  found  inter- 
calated.    These  rocks  contain  slate  rocks,  conglomerates,  dark 
limestone,  and  fine-grained  slates  of  various  shades  of  purple,  blue 
and  green.     In  the  Cambrian  rocks  the  organic  remains  consist  of 
a  few  fossil  brachiopods,  polypa'ria,  or  coral  animals,  &c. 

25.  How  does  the  palaeozoic  formation  differ  from  the  primitive  rocks  ? 
In  what  manner  were  the  palae'ozoic  formations  produced  ? 

26.  At  the  period  of  the  palae'ozoic  formation,  what  description  of  organ- 
ized  beings  lived  on  the  earth  ? 

27.  How  is  the  transition  or  palae'ozoic  formation  divided  ? 

28.  How  is  the  Cambrian  System  of  rocks  characterized  ?     From  what 
is  its  name  derived  ?    What  is  the  geological  position  of  the  Cambrian 
System  ? 


28 


SILURIAN  SYSTEM— FOSSILS. 


29.  The  SIHJ'RIAN  SYSTEM  (from  the  Silures,  or  Siluri,  the  an- 
cient Britons  who  inhabited  the  region  where  these  strata  are  most 
distinctly  developed)  is  next  above  the  Cambrian,  It  is  subdi- 
vided into  the  upper  and  lower  Silurian  strata.  In  its  mineral 
composition  it  so  closely  resembles  that  of  the  Cambrian  that  it  is 
often  difficult  to  distinguish  them.  These  strata  are  entirely  of 
marine  origin,' and  many  of  the  beds  (as  the  well-known  Dudley 
limestone)  are  composed  of  shells,  corals,  crinoidea,  and  those  pe- 
culiar crustaceans  termed  trilobiles  (jig.  4),  held  together  by  a 
calcareous  cement. 


30.  The  presence  of  these  fossil  animals  is  characteristic  of  the 
Silurian  and  Devonian  Systems  of  strata,  because  they  are  rarely 
met  with  in  other  situations.  They  are  found  entombed  in  slate 
and  dark  limestone. 

Trilobitcs,  from  their  extraordinary  form  and  appearance,  have,  for  more 
than  a  hundred  and  fifty  years,  been  objects  of  great  interest  to  the  natu- 
ralist and  of  wonder  to  the  general  observer,  and  have  long  been  provin- 
cially  termed  Dudley  insects  or  locusts.  The  most  common  examples  con- 
sist of  a  convex,  oblong  body,  divided  transversely  into  three  principal 
parts,  and  longitudinally  into  three  lobes,  by  two  deep,  parallel  furrows  ; 
from  this  last  character,  by  which  the  family  is  recognised  among  natural- 
ists, the  name  Trilobite  (from  the  Latin  trcs,  three,  and  lobus,  lobe)  has  been 
derived.  These  fossils  are  the  carapaces,  or  shells,  of  crustaceans,  belonging1 
to  an  extinct  family,  which  comprises  many  genera,  and  numerous  species. 

The  class  of  crustaceans  consists  of  two  groups,  namely  :  those  with  eyes 

*  Explanation  of  Fig.  4.  1  .-A'saphus  Caudatus. — 2.  A'saphus  Buchii. — 
3.  Caly'mene  Blumenbachii. 

29.  How  is  the  Silurian  System  characterized  ?     How  does  it  differ  from 
the  Cambrian  System  ?     What  is  the  origin  of  its  name  ?     What  are  tri- 
lobites  ? 

30.  Of  what  systems  of  rocks  are  trilobites  characteristic  ?      » 


FOSSIL  REMAINS — TRILOBITES. 


29 


supported  on  movable  peduncles,  as  the  crab  and  lobster,  and  those  with 
eyes  fixed ;  the  extinct  order  of  trilobites  belongs  to  the  last. 

The  Caly'mene  Blumenbachii  (Jig.  4,  No.  3)  is  named  after  the  celebrated 
German  naturalist  Blumenbach ;  the  generic  name,  caly'mene  (formed  from 
the  Greek  kekalumene,  concealed)  was  devised  to  express  the  obscure  nature 
of  this  genus  of  trilobites.  It  is  found  expanded,  with  its  under  surface 
attached  to  and  blended  with  the  limestone,  or  coiled  up.  The  head  is  large, 
convex,  rounded  in  front,  with  a  broad  border,  and  divided  into  three  lobes 
by  two  longitudinal  depressions.  It  has  two  compound  eyes  with  numerous 
facets,  situated  at  the  back  of  the  head  remote  from  each  other.  This  spe- 
cies is  from  one  to  four  inches  in  length.  MantelL 

"  It  is  a  curious  fact,"  says  Mr.  T.  A.  Conrad  (Palaeontologist,  State  of 
New  York,  1838),  "  that,  whilst  the  Caly'mene  Blumenbachii  ceased  to 
exist  in  New  York  after  the  final  deposition  of  the  Trenton  series,  it  escaped 
into  remote  seas  and  lived  in  the  era  of  the  Dudley  limestone." 

In  another  genus,  A'saphus  (from  the  Greek  asaphes,  obscure),  the  cara- 
pace is  wide  and  much  depressed  (Jig.  4,  Nos.  1,2);  the  middle  lobe  distinct, 
the  cephalic  portion  rounded  in  front,  and  terminating  posteriorly  in  a  sharp 
process  on  each  side.  The  eyes  are  compound,  and  each  contains  four  hun- 
dred spherical  lenses.  Some  kinds  of  A'saphus  have  remarkably  long, 
pointed,  caudal  appendages,  or  tails,  (fig.  4,  No.  1).  Some  American  species 
of  this  group  are  eighteen  inches  in  length.  Mantell. 

31.  Besides  the  trilobites,  the  remains  of  other  animals  are  found 
in  the  Cambrian  and  Silurian  Systems.  They  mostly  belong  to 
the  division  of  brachiopod  mollusks.  Among  those  which  are 
regarded  as  characteristic  of  the  Silurian  System  are  the  Orthis 
orbicularis  (fig.  5),  Orthis  testudinaria  (Jig.  6) :  the  orthis  is  a 
circular  shell  with  a  striated  surface,  and  long,  narrow  hinge; 


Fig.  5. — Orthis  orbicularis.  Fig.  6. — Orthis  testudinaria. 

the  Orthoceras  (Jig.  7),  (from  the  Greek  orthos,  straight,  and  keras, 
horn) ;  the  Lithuites  (Jig.  8),  of  large  dimensions ;  the  Productus 


Fig.  7. — Orthoceras  conica. 


Fig.  8. — Lithuites  giganteus. 


31.  Name  some  of  the  fossils  found  in  the  Cambrian  and  Silurian  Sys. 
terns.    To  what  division  of  the  animal  kingdom  do  these  fossils  belong  ? 


80 


PRODUCTUS.— SPIRIFER.— TEREBRATULA. 


(Jigs.  9,  10),  (Latin,  drawn  out,  dikted) ;  or  Leptena  (from  the 
Greek  leptos,  slender). 


Fig.  9. — Productus  depressus. 


Fig.  10. — Productus  antiquatus. 


"  The  genus  Productus  has  received  its  name  from  a  peculiarity  observed 
in  several  species  where  the  dorsal  valve,  after  having  attained  a  certain 
magnitude,  bends  suddenly  at  right-angles  to  its  former  direction,  and  is 
then  continued  irregularly,  sometimes  being  produced  (extended)  to  a  con- 
siderable  length.  The  whole  shell  is  usually  covered  with  striae  and  spines, 
which  in  some  species  are  numerous  and  very  long,  and  which  appear  to 
have  been  movable,  doubtless  serving  a  purpose  in  the  animal  economy." 
Ansted. 

32.  The  Spi'rifer  (Jig.  11),  (from  the  Latin  spira,  a  wreath  or 

twisting,  and  fero,  I  bear),  is  a  bra- 
chiopod,  closely  resembling  the  tere- 
•— .  bratula  in  many  important  characters, 
/  but  differing  from  it  in  the  singular 
•'     spire  of  calcareous  matter   passing 
across  the  interior  of  the  shell,  and 
from  which  the  name  of  the  genus 
is  derived.     The   species  are  very 
Fig.U.-Spirifer  tngonahs.     numerous?  and,  next  to  terebratula, 

are  'the  most  abundant  of  all  brachiopod  fossils. 

33.  The  genus  Terebru'tula  (Jigs.  12,  13, 14),  (from  the  Latin 

terebro,  I  bore  ;  bored,  alluding  to  the  perforated 
beak).     Throughout  the  whole  of  the  palsc'ozoic 


Fig.  12.—  Terebra- 
tula digona. 


Fig.  13.— Terebra- 
tula octoplicata. 


Fig.  14.—  Terebratula 
navicula. 


formation,  certain  species  of  terebra'tulse  are  found.  This  remark- 
able genus,  which  has  in  the  present  day  some  representatives  in 
the  existing  seas,  appears  to  have  been  created  among  the  very  first 
of  the  inhabitants  of  the  first  formed  ocean,  and  to  have  retained 


32.  What  is  the  peculiarity  of  the  Spi'rifer  ? 

33.  What  are  terebratula}  ? 


PENTAMERUS— POLYPARIA. 


its  place  longer  than  any  other.  From  the  incalculable  antiquity 
of  their  lineage,  the  terebratulae  have  been  humorously  styled  the 
Fossil  aristocracy. 

34.  The  genus  Pentame'rus  (Jigs.  15, 16, 17 — from  the  Greek 
pente,  five,  and  meros,  parts,  or  cells),  contains  four  known  species, 
all  of  which  belong  to  the  Silurian  rocks.     In 
this  genus,  the  lesser  valve  is  divided  inter- 
nally by  two  parallel  walls,  or  septa,  running 
close   together    lengthwise   along  the   shell, 
forming  three  cells  ;  the  other  valve  also  has 
a  septum  or  wall,  which  is  forked  towards  the 
beak  of  the  shell,  and  divides  it  into  two  cells  ; 
thus  forming  the  five  cells  to  which  it  is  in- 
debted for  its  generic  name.     The  casts  of 
these  shells  (fig-  15),  often  have  fissures,  pro- 
duced by  the  decomposition  of  the  septa ;  and  occasionally  these 
cavities  are  occupied  by  calcareous  spar. 


Fig.  15. — Cast  of  the 
Pentamerus  lavis. 


Fig.  16. — Pentame'rus  Knightii.  Fig.  17.— Section  of  same  Shell. 

35.  Of  the  polypa'ria  or  corals  which  existed  when  the  Silurian 


Fig.  18—Cyathophyllum  turbinatum.  Fig.  19. — Catenipora  escharoides. 

rocks  were  formed,  representations  of  two  genera  are  given.     The 

34.  How  is  the  genus  pentame'rus  characterized  ? 

35.  Did  corals  exist  in  the  Cambrian  and  Silurian  rocks  ? 


32  ORGANIC  REMAINS—DEVONIAN  SYSTEM. 

Cyatho'phyllum  (Jig.  18),  (from  the  Greek,  kuathos,  a  cup,  and 
phullon,  a  flower).  The  abundance  of  corals  of  this  genus  in  the 
Silurian  system  proves  that  the  seas  of  that  epoch  must  have 
teemed  with  these  zo'ophytes.  The  Cate'nipora  (Jig>  19),  (from 

the  Latin,  catena,  a 
chain,  and  porus,  a 
pore).  The  oval  form 
of  the  cells  when  united 
laterally,  and  the  flexu- 
ous  disposition  of  the 
lamellae,  give  rise  .in 
transverse  sections  to 
elegant  catenated  mark- 
ings, from  which  ap- 
pearance the  fossil  has 
received  the  name  of 
chain-coral.  The  spe- 
cies figured  (Jig.  19), 
is  common  in  Silurian 
limestone,  and  some- 
times forms  hemispher- 
ical masses  more  than  a 
foot  in  diameter. 

36.  The  organic  re- 
mains of  the  Cambrian 
system  differ  from  those 
of  the  Silurian  system 
in  being  less  developed ; 
the  genera  and  species 
of  mollusks  and  corals 
found  in  both  are  alike. 

37.  The   DEVONIAN 
SYSTEM  (so  called  be- 
cause it  is  largely  deve- 

Fig.  20.*— Fossil  Fishes  of  the  Devonian  System,  loped    in    Devonshire, 

England)  forms  the  su- 
perior part  of  the  preceding  formation.     It  appears  to  be  composed 

*  Explanation  of  Fig.2Q. — 1.  Pterichthys  cornutus,  seen  from  above — 
(Pterichthys,  from  the  Greek,  pteron,  wing,  and  ichthos,  fish  :  cornutus,  La- 
tin, horned.  The  horned  wing  fish).  2.  Coccosteus  oblongus.  These 
figures  are  restored  with  great  accuracy  from  the  best  preserved  specimens 
hitherto  discovered.  The  British  species  of  fossil  wing-fishes,  of  which 
five  or  six  are  known,  are  all  very  small,  varying  in  length  from  one  to 
eight  or  ten  inches.  But  in  the  Devonian  strata  of  Russia  enormous  spe- 
cies occur ;  the  spines  of  some  of  them  exceed  a  foot  in  length.  See  Man- 
tell1  s  Medals  of  Creation.  London,  1844. 


36.  How  do  the  fossils  found  in  the  Cambrian  rocks  differ  from  those  of 
the  Silurian  System  ? 


DEVONIAN  SYSTEM. 


33 


at  first  of  pudding-stone,  with  which  it  commences,  and  to  pass  to 
sandstone,  with  which  it  alternates  at  different  places.     Then  come 


Fig.  21. — Caryopliy'llia  fastigia'ta. 


Fig.  23. — Calceola  sandalina. 


Fig.  22,—Amplexus  coralloi'des 


sandstone-schists,  more  or  less  fine,  different  species  of  schist,  lime- 
stones, alternating  with  each  other,  in  the  midst  of  which  are  found 
beds  of  anthracite.     These  va- 
rious materials  are  differently 
developed   in   different   coun- 
tries :  in  England   the   sand- 
stones   predominate.       They 
form  the  old  red  sandstone, 
comprising  strata  of  clay  and 
marl  of  different  colours.     In 
other    places   the    limestones 
prevail    with    different   clay- 
slates,  or  chloritic  schists,  some- 
times intercalated  with  schistose          FiS'  M'—Clyme'ma  linea'ris. 
quartz,  as  in  Devonshire,  and  sometimes  almost  alone,  as  in  Corn- 
wall. 


37.  What  is  the  origin  of  the  term   Devonian  System  ?     What  is  its 
geological  position  ?    Of  what  rocks  does  it  consist  ? 


34 


SLATE— SYSTEMS  OF  ROCKS. 


38.  This  system  presents  us  with  depots  of  the  oldest  com- 
bustible materials  known ;  and  we  find  in  it  ferns,  ca'lamites,  divers 
species  of  plants,  differing  but  little  from  the  plants  found  in  the 

coal   formation  which 


immediately  follows. 
We  here  find  also  a 
great  many  pol'yps 
more  or  less  analogous 
to  the  Caryophyllia 
(fig.  21) ;  Jimplexus 
(fig.  22),  by  some  re- 
garded as  polyps  and 
by  others  as  chamber- 
ed shells,  which  are 
found  nowhere  beside. 


Fig.  25. — Megalodon  cuculla'lus.  -  ~, ,.  * 

so   nearly  resembling 

certain  productus,  appears  to  be  characteristic  of  the  Devonian 
rocks  ;  and  perhaps  also  the  Clymenia  Hnearis  (Jig.  24),  a  cham- 
bered shell  with  aventral  siphon.  Certain  peculiar  bivalves  are 
also  found  (Jig.  25);  some  brachiopods,  and  among  others  the 
Terr ebra' tula  porrecta  (Jig.  26). 

39.  Slates,  so"  extensively  used  for  roofs,  are  furnished  from  this 

group  of  ancient  rocks ; 
and  on  many  we  find  im- 
pressions of  trilobites.  The 
upper  part  of  the  transition 
strata  often  contains  car- 
boniferous materials,  some- 
times disseminated  among 
the  schists,  and  at  others 
constituting  more  or  less  ex- 
tensive masses,  wrhich  are 

generally  composed  of  anthracite,  though  sometimes  of  bituminous 

coal. 

40.  These  three  systems  of  rocks,  namely  the  Cambrian,  Silu- 
rian and  Devonian,  which  are  not  easily  distinguished  from  each 
other,   are   found  in    most    countries    of  Europe,   where    their 
assemblage  constitutes  the  greater  part  of  what  is  named  the 
transition  or  palaeozoic  formation.     They  abound  in  Brittany : 
there  the  anthraciti'ferous  mass  forms  a  stripe  along  the  Loire,  ex- 
tending from  Maine  to  Morbihan,  as  well  as  other  depots  in  Sarthe 
and  Mayenne.     These  rocks  are  found  through  the  whole  chain 


Fig.  26. —  Terrebra'tula  porrecta. 


38.  What  fossils  are  found  in  the  Devonian  System  ? 

39.  What  useful  material  is  found  in  the  Devonian  System  ? 

40.  What  systems  of  rocks  constitute  the  palaeozoic  formation  ? 
is  this  formation  met  with  ? 


Where 


POSITIONS  OF  THE  DIFFERENT  STRATA.  35 

of  the  Pyrenees,  in  the  southern  part  of  Cevennes,  in  the  moun- 
tains of  Forez  and  Beaujolais,  and  in  some  parts  of  Vosges.  They 
form  all  the  Hundsruck,  Eiffel,  and  Ardennes  and  the  southern 
part  of  Belgium.  They  are  met  with  in  Hartz,  in  Saxony,  and 
different  parts  of  Germany,  Sweden,  and  Norway ;  and  they 
abound  in  England  as  well  as  in  the  United  States.  They  every- 
where offer  a  matrix  for  anthracite. 

41.  Geologists  are  not  agreed  as  to  the  natural  limit  between 
these  strata  and  those  of  a  more  recent  order,  generally  designated 
under  the  name  of  secondary  formation ;  but  most  authors  con- 
sider the  period  of  transition  to  cease  beneath  the  carboniferous 
rocks  and  the  coal  measures. 

42.  While  the  different  stratified  rocks  we  have  spoken  of  were 
in  progress  of  formation,  there  were  effusions  of  granite  and  other 
igneous  rocks  on  their  surface,  and  these  geological  convulsions 
have  produced  in  the  strata  elevations  and  changes  of  direction,  so 
that  many  of  them  are  raised  up  and  are  very  much  inclined  and 
in  some  instances  almost  vertical.     It  was  during  one  of  these 
revolutions  that  the  mountains  of  Westmoreland  and  Cornwall,  in 
England,  were  suddenly  elevated ;  a  part  of  those  of  Brittany,  and 
Bigorre,  &c.,  in  France,  of  the  Hundsruck,  Eiffel,  and  Hartz,  in 
Germany,  and  many  other  mountain  chains.     The  superior  transi- 
tion strata,  which  were  formed  subsequently  to  this  convulsion  and 
rested  on  the  edge  of  strata  thus  upheaved,  were  in  turn  dislocated 
and  raised  up,  and  according  to  the  observations  of  a  French  geo- 
logist, Elie  de  Beaumont,  this  elevation  appears  to  have  been  ante- 
rior to  the  formation  of  more  recent  rocks  than  those  we  have  yet 
mentioned,  and  to  correspond  with  the  eruption  of  masses  of  igne- 
ous rocks  of  the  mountains  of  Vosges,  known  under  the  name  of 
buttons  of  Alsace  and  Comte.     The  elevation  of  the  hills  of  Bocage, 
in  Calvados  and  several  mountain  chains  in  England,  Germany 
and  Poland  appears  to  have  occurred  about  the  same  time. 

The  following  diagram  (fig.  27),  represents  the  several  strata 
we  have  described,  in  a  horizontal  position,  one  lying  above  the 
other,  and  embraces  the  granite  or  plutonic  rocks  below,  next  the 
aqueous  or  metamorphic  rocks,  and  above  the  whole,  the  transition 
formation,  consisting  of  the  Cambrian,  Silurian  and  Devonian  Sys- 
tems of  strata. 


{Devonian  Sys'em—  Fossils- 

-Fishes. 

Silurian  System—  Fossils—  ' 

Frilohi'es 

rv_  07 

-Polyps. 

•Tig*  <*/• 

{Arzillaceous-«chist. 

Mica-schist. 

Gneiss. 

Granite—  Pluionic  Rocks. 

A                       B 

41.  How  is  the  transition  separated  from  the  secondary  formation? 

42.  What  is  supposed  to  have  happened  while  the  stratified  rocks  were 
being  formed  ? 


36  THIRD  GEOLOGICAL  EPOCH. 

If  we  suppose  the  strata  to  have  been  in  this  position  at  the  time 
of  a  geological  convulsion,  such  as  we  have  alluded  to  above,  and 
that  the  granite  should  force  its  way  upwards  at  A  or  B,  we  should 
find  perhaps  all  the  relations  of  the  strata  changed,  presenting 
something  like  the  arrangement  represented  in  the  following  figure. 


Transition.     Stratified. 


Fig.  28. 


The  above  figure  represents  the  effect  of  the  sudden  rising  up 
of  a  mass  of  granite,  bursting  and  breaking  through  all  the  strata 
that  were  lying  above  it.  Instead  of  a  horizontal  level  surface,  as 
in  fig.  27,  we  have  a  mountain  of  granite,  from  the  lowest  stratum, 
overtopping  all  the  more  recent  formations ;  and  the  ends  of  the 
several  strata,  where  they  were  broken  to  give  passage  to  the 
granite,  are  brought  up  towards  the  earth's  surface,  represented  by 
the  dotted  line.  In  such  a  case  as  we  here  suppose,  it  would  be 
very  difficult  for  one  who  had  not  studied  the  subject  to  determine 
which  stratum  was  first  formed :  it  might  seem  to  him  that  inas- 
much as  he  finds  the  granite  occupying  the  highest  point,  and  the 
transition  rocks  the  lowest,  that  the  granite  is  of  the  last  or  most 
modern  formation. 


LESSON  III. 

THIRD  GEOLOGICAL  EPOCH. — Secondary  Formation — Carbonife- 
rous Formation — Old  Red  Stone — fossils — Coal  Formation — 
Fossils — Extent  of  Coal  Measures. 

FOURTH  GEOLOGICAL  EPOCH. — New  Red  Sandstone — Fossils — 
Triassic  System — Bunter  Sandstein — Mushelkalk — Keu'per 
— Ammonites — Fossils. 

FIFTH  GEOLOGICAL  EpocH.~-Zz'«s,  or  Lia'ssic  System — Fossils 
— I'chthyosau'rus — Plei'siosau'rus — Pteroda' ctylus — O'olitic 
System — Fossils. 

THIRD  GEOLOGICAL  EPOCH. 
Secondary  Formation — Carboniferous  Formation. 

1.  After  the  great  revolutions  which  seem  to  have  terminated 
the  ancient  period  commonly  designated  as  the  transition  epoch, 


OLD  RED  SANDSTONE,  &c.  87 

the  earth  appears  to  have  remained  in  a  state  of  repose  for  a  long 
time,  which  permitted  new  generations  of  organized  beings  to  mul- 
tiply on  its  surface,  and  mineral  substances,  carried  by  the  waters, 
to  be  deposited  in  great  layers,  and  to  entomb  in  their  substance 
the  solid  remains  of  the  exuviae  of  contemporaneous  animals  and 
plants. 

2.  The  first  deposits  which  took  place  during  this  geological 
epoch,  constituted  the  strata  of  sandstone,  conglomerate,  (an  assem- 
blage of  fragments  of  rocks  and  pebbles,  cemented  together  by 
other  mineral  matter,)  clay,  calcareous  rocks,  &c.,  and  from  their 
union  resulted  the  formation  called  by  geologists  the  old  red  sand- 
stone, on  account  of  its  antiquity  and  prevailing  colour.     But  this 
state  of  things  was  soon  changed,  and  there  was  formed,  slowly 
and  gradually,  at  the  bottom  of  the  waters,  an  immense  stratum  of 
calcareous  rocks,  seven  or  eight  hundred  feet  in  thickness ;  then 
the  sandy  sediment  alternated  with  these  limestones,  and  above  this 
great  formation,  designated  under  the  name  of  carboniferous  (coal- 
bearing)  limestone,  numerous  strata  of  sandstone,  schistose  cky 
and  coal  were  accumulated. 

3.  The  fossils  of  the  old  red  stone  are  somewhat  numerous,  and 
belong,  for  the  most  part,  to  marine  animals,  among  which  was  a 
fish  of  strange  form,  called  cephalaspis,  (from  the  Greek,  kephale, 
head,  and  aspis,  shield  or  buckler,)  because  its  head  resembles  a 
kind  of  buckler  (Jig.  29). 


Fig.  29. — Cephalaspis  Lyellii. 

The  remains  of  the  genus  Cephalaspis  (fig.  29)  are  found  chiefly  in  the 
upper  beds  of  the  old  red  sandstone  of  Scotland,  but  also  in  Herefordshire 
and  Wales.  "  In  this  genus,  the  head  is  very  large  in  proportion  to  the 
body,  and  occupies  nearly  one-third  of  the  entire  length  of  the  animal ;  its 
outline  is  rounded  and  crescent-shaped,  and  the  lateral  horns  slightly  incline 
towards  each  other,  their  points  being  nearer  to  one  another  than  they  are 
to  the  round  part  of  the  snout.  The  middle  of  the  head  is  elevated,  and 
the  sides  dilated,  so  as  to  overlap  the  body,  and  extend  considerably  behind 
it;  but  perhaps  the  head  only  appears  to  extend  so  far,  owing  to  accidents 
of  displacement  since  the  death  of  the  animal.  The  eyes  are  placed  in  the 
middle  of  the  shield,  near  to  each  other,  and  are  directed  straight  upwards. 
It  is  imagined  that  the  pointed  horns  of  the  crescent  may  have  been  useful 

1.  What  happened  after  the  termination  of  the  transition  period  of  geo- 
logical history  ? 

2.  What  were  the  first  deposits  after  the  transition  period  ? 

3.  What  is  the  character  of  the  fossils  of  the  old  red  sandstone  ?     What 
is  the  Cephalaspis  ? 

4 


CARBONIFEROUS  LIMESTONE. 


as  defences  when  the  fish  was  attacked  by  the  powerful  cephalopoda  which 
inhabited  the  ocean  at  the  period  of  its  existence."  The  head  and  body  are 
covered  with  scales,  of  peculiar  and  varied  shapes.  Ansted. 

4.  The  carboniferous  limestone,  also  called  mountain  limestone, 
and  metalliferous  limestone,  affords  several  varieties  of  black, 
bluish  grey,  and  variegated  marbles,  as  well  as  ores  of  lead,  cop- 
per, zinc,  &c.  It  contains  a  great  number  of  organic  remains, 
such  as  divers  polyparia  cyathophylla  (Jig.  18),  madrepora,  &c., 
encrinites,  which  belong  to  the  division  of  crinoidea  (fig.  30). 

It  also  contains  the  remains  of  a  number  of  mollusks,  as  the 
orthoceras  lateralis  (fig.  31) ;  goniatites  (fig.  32),  which  resem- 
ble the  nautilus ;  bellerophons  (fig.  33),  which,  with  analogous 
forms,  are  not  chambered ;  euomphalus  (fig.  34) ;  spirifers  and 
productus  in  great  variety,  especially  (figs.  35,  36). 

The  Crinoidece,  (from  the  Greek,  krinon,  a  lily,  and  eidos,  resemblance,) 
a  family  belonging  to  the  class  of  radiate  animals,  are  remarkable  for  the 
simplicity  of  their  organization,  and  the  peculiarly  com. 
plicated  structure  of  their  skeleton.  The  animal  resem- 
bled a  true  polyp  or  coral  animalcule  ;  the  body  consisted 
of  a  gelatinous  tube,  contracted  at  one  extremity,  by 
which  it  was  attached,  and  furnished  at  the  opposite  end 
with  a  variable  number  of  delicate  contractile  filaments 
placed  around  the  opening  which  represents  the  mouth. 

The  calcareous  skeleton  was  formed  within  the  tube, 
and  consisted  of  thousands  of  regularly-shaped  pieces, 
kept  together  by  the  tough  membrane  which  enclosed 
them  during  the  life  of  the  animal. 

The  family  is  divided  into  genera,  according  to  the 
form   of  the  stems,  or  according  to   its  general  shape. 
When  the  arms  or  stems  are  round,  it  is  an  Encrinite  ; 
Fig-  30  ^-Cyatho-  t'ie  cyathocrinites    (Jig.  30)   takes   its   name    from   the 
criniles  planus.     Greeki  kuathos,  a  cup,  and  krinon,  lily. 

Many  limestones  are  composed  almost  exclusively  of 

the  remains  of  species  of  Crinoidea,  as  at  Lockport,  New  York  ;  and  various 
genera  of  this  family  are  found  in  Alabama,  near  Huntsville. 

The  Orthoceras^  or  orthoccratite,  (from  the  Greek,  orthos, 
straight,  and  keras,  horn,)  is  straight,  or  slightly  bent,  cylin- 
drical, slightly  conical,  many-chambered  cell  ;  the  chambers 
are  separated  by  plain  septa,  which  are  concave  towards  the 
larger  end,  and  pierced  with  a  siphuncle. 

Go'nialites  (Jig.  32),  (from  the  Greek, 
gdnia,  an  angle,)  is  a  genus  of  extinct 
cephalopods,  which  inhabited  a  cham- 
bered shell  resembling  that  of  the  am- 
monites. 

Belle'rophon  (Jig.  33),  (from  the  Greek, 
Bellerophontes,  the  name  of  a  fabulous 
hero,)  a  genus  of  cephalopods  which  in- 

. Ortho-  habited  chambered  shells  similar  to  those 

ceras  lateralis.  of  the  argonaut  and  nautilus. 


Fig.  32.—Go'nia. 
tiles  cvolutus. 


4.  What  are  the  characters  of  the  carboniferous  limestone  ? 


COAL  FORMATION. 


The  Euomphalus  (fig.  34),  (from  the  Greek,  £U,  properly,  and  omphalos 
the  navel,)  was  a  gasteropod  mollusk.  The  shell  is 
often  exceedingly  thick,  and  is  divided  irregularly  into 
a  number  of  compartments  or  chambers,  provided  with 
a  solid  tube  running  through  them,  entirely  shutting 
off  that  part  of  the  shell  in  which  the  animal  dwelt, 
from  the  smaller  and  uninhabited  portion.  These 
empty  spaces  served,  no  doubt,  as  floats,  rendering  the 
whole  mass  of  the  shell  and  animal  sufficiently  light 
to  move  easily  in  the  water.  Ansled. 

Fig.  33.—Belle'ro- 
phon  coslatus. 


Fig.  34. — Euom'pkalus  penta'ngula'tus. 


Fig.  35. — Spi'rifer  glaber. 


Fig.  36. — Productus  Martini. 


5.  At  the  period  of  the  Coal  Formation,  the  earth  appears  to 
have  been  occupied,  in  a  great  part,  by  a  deep  sea  studded  with 
islands,  covered  by  an  abundant  and  luxuriant  vegetation.     The 
then  existing  plants  differed  very  much  from  those  now  living ; 
hundreds  of  different  species  are  known,  but  almost  the  whole  of 
them  belonged  to  the  class  of  vascular  cryptoo-a'mia :  they  are 
principally  ferns,  equisita'ceae,  lycopodia'cere,  that  is,  plants  of  a 
very  simple  structure  but  of  gigantic  size.     The  tree-ferns,  of 
•which  existing  species  do  not  exceed  20  or  25  feet  in  height,  even 
in  the  torrid  zone,  and  generally  not  more  than  8  or  10  feet,  then 
grew,  in  localities  far  beyond  the  tropics,  from  40  to  50  feet  high ; 
and  other  plants,  whose  representatives  of  the  present  time  are 
mere  herbs,  then  rose  to  60  feet  in  height. 

6.  In  that  period,  there  were  also  insects  resembling  weevils  and 
neuro'ptera  of  the  present  day ;  scorpions,  which  differed  from  the 

5.  What  was  the  condition  of  the  earth  at  the  period  of  the  coal  formation  ? 


40 


COAL  FORMATION. 


existing  species  in  the  number  of  their  eyes  ;  fresh-water  mollusks, 
and  very  remarkable  fishes,  which,  in  certain  respects,  resembled 
reptiles,  and  had  their  bodies  covered  by  thick  solid  plates. 

7.  The  debris  of  the  plants  of  that  period,  accumulated  in  im- 
mense masses  and  altered  by  time  and  other  causes,  were  trans- 
formed into   the   combustible   material,  which  is   so  immensely 
valuable,  known  under  the  name  of  coal. 

8.  The  deposits  of  coal  begin,  in  France,  ordinarily  with  pud- 
ding-stones formed  of  the  debris  of  different  rocks  from  the  sur- 
rounding country,  often  comprising  gigantic  blocks  scarcely  rounded. 
Sometimes  finer  pudding-stones  alternate  with  sandstone,  which 
always  constitutes  a  chief  part  of  the  deposit.     Very  numerous  va- 
rieties of  these  sandstones,  arising  from  the  size  of  the  grains  of 
quartz  and  the  quantity  of  argilla'ceous  matter  entering  into  their 
composition,  are  found  ;  they  are  frequently  micaceous  and  schistose  ; 
they  contain  beds  of  clay  -slate  and  bituminous  schist,  which  are 
sometimes  very  thick,  but  rarely  calcareous  strata.     The  masses 
of  coal  are  scattered  throughout,  but  are  always  separated  from  the 
sandstone  by  beds  of  slate  ;  these  are  at  first  nearly  pure,  then 
mixed  with  the  combustible,  and  finally  are  represented  alone  above 
the  deposit. 

9.  Besides  the  coal  formed  by  the  accumulation  of  the  debris  of 

decomposed  plants,  the  coal-measures  con- 
tain a  great  number  of  the  remains  of 
plants  which  retain  their  organic  charac- 
ters :  the  stems  and  trunks  of  trees  are 
found  in  the  sandstone  ;  the  leaves  have 
left  their  imprints  perfectly  preserved  in 
the  schists  and  clays  which  accompany 
the  coal. 

10.  The  impressions  of  ferns  are  ex- 
tremely numerous  ;  among  them  is  the 
Pecopteris  (fig*  37),  of  which  the  leaflets, 
but  little  detached  from  the  pedicle,  are 
joined  in  a  single  leaf,  deeply  incised,  in 
which  we  recognise  a  principal  nervure, 
from  which  the  secondary  nervures  arise 
perpendicularly  ;  the  Sphfcnopteris  (Jig. 
38),  analogous  to  the  preceding,  but  in 
which  the  leaflets  are  more  distinct,  deeply 
lobed,  and  have  the  nervures  radiate  al- 
most from  the  base  ;  the  Neuro'pteris 
Fig.31.  -Pecopteris  aquilina.^g  which  als0  has  the  leaflets  de- 


6.  What  animals  existed  at  that  period  ? 

7.  From  what  was  coal  formed  ? 

8.  In  what  kind  of  rock  is  coal  found  ? 

9.  In  what  do  we  find  impressions  of  plants  ? 


COAL  FORMATION. 


41 


tached,  but  entire  and  rounded,  and  the  nervures  arise  very  obliquely 
from  the  middle  nervure,  and  afterwards  frequently  divide  ;  and  a 
great  number  of  other  genera  founded  on  the  form  of  their  leaflets 


Fig.  3d. — Sp/tanopleris  Haninghausi.  Fig.  39. — Neuropteris  Loshii. 

and  the  arrangement  of  their  nervures.  We  also  find  various  other 
plants,  the  families  of  which  are  uncertain,  such  as  the  Spheno- 
phyllites  (fig.  40),  Jlnnula'ria,  &c.  (fig.  41),  which  are  very 
abundant  in  certain  localities. 


Fig.  40. — Spheno'pJiyllum 
dentatum. 


Fig.  41. — Annula'ria  brevifolia. 


11.  True  equisita  appear  to  have  existed  in  the  coal-measures ; 
but  we  are  also  led  to  place  in  the  same  family  certain  stems, 
grooved  lengthwise,  with  joints  at  intervals  from  which  branches 
sometimes  spring  (Jigs.  42,  43).  These  stems,  called  ca'lamites, 

10.  Name  some  of  the  genera  of  fossil  plants  found  in  coal-beds. 

4* 


42 


COAL  FORMATION. 


are  often  found,  like  all  the  rest  of  those  of  which  we  speak,  con- 
verted into  argillaceous  matter,  which  has  become  hard,  or  into  car- 
bonates of  iron,  but  rarely  into  silicious  matter.  The  external 
vegetable  tissue  is  frequently  found  to  have  passed  into  a  carbonous 
state. 


Fig,  42._ Calami'tes  suckovii.  Fig.  43. — Calami'tes  cann&fo'rmis. 

12.  The  Lycopodia'cex  embrace  various  species  of  Lepidode'n- 
drons  (figs.  44,  45),  of  which  entire  trees  have  been  sometimes 
found,  upwards  of  sixty  feet  in  height.  Their  trunks  present 
rhomboidal  projections,  spirally  arranged,  which  clearly  exhibit 
near  the  top  cica'trices  of  leaves. 


Fig.  U.—Lepidode'ndron  crena'tum.         Fig.  te.—Lepidode'ndron  e'legans. 

13.  The  Sigilla'nse  (fig.  46)  seem  to  range  themselves  next  to 
the  Cyca'decD ;  their  stems,  flattened  by  pressure,  are  channelled 
lenothwise  but  not  articulated,  and  the  cica'trices  are  arranged  in  a 
longitudinal  series.  The  stems,  called  stigma'ria  (Jig.  47),  are, 

~~11.  What  genera  belonging  to  the  family  of  equisita'cere  are  found  in 
coal-beds  ? 

12.  What  fossil  plants  of  the  family  of  lycopodia'cesB  are  found  m  coal- 
measures  ? 


COAL  FORMATION. 


43 


according  to  Ad.  Brongniart,  probably  only  the  roots  of  plants,  the 
body  of  which  is  traversed  by  a  ligneous  axis  surrounded  by  soft 
fleshy  parts. 


Fig.  46.—Sigilla'ria  pachyde'rma. 


Fig.  47. — Stigma'ria  Jicoi'des. 


14.  The  co'nifers,  which,  from  the  consistence  of  their  wood, 
seem  to  have  participated  largely  in  the  formation  of  carbonaceous 
matter    in    different 

strata,  present  us,  in 
the  different  coal- 
measures,  especially 
in  the  upper  beds, 
species  approxima- 
ting to  the  arauca'ria 
in  their  spirally-ar- 
ranged sessile  leaves. 
M.  Ad.  Brongniart 
refers  the  whole  of 
them  to  the  genus 
Walchia  of  M.  Stern- 
berg,  of  which  two 
species,  with  their 
leaves  and  fruit,  are 
here  figured,  (Jig. 

15.  Animal    re- 


Fig.  48.— -a  Walchia  Schlatheimii. 
b  Walchia  Hypnoidcs. 


mains  are  not  very 
common  in  coal-mea- 
sures ;  stih1  some  are  found,  and  even  in  great  numbers  in  certain 


13.  What  are  sigillariae  ?     What  are  stigmarise  ? 

14.  What  genus  of  conifers  is  found  fossilized  ? 


44 


COAL   FORMATION. 


localities.  From  the  calcareous  beds,  subordinate  to  these  sand- 
stones, in  the  environs  of  Edinburgh,  Dr.  Hibbert  has  collected  the 
remains  of  enormous  sauroid  fishes,  the  strong  and  longitudinally 
striated  teeth  of  which,  as  well  as  the  whole  osseous  system,  remind 


Fig.  49. — Lower  Jaw  of  the  Holopticus  Hibberti. 

us  of  the  largest  sized  reptiles.  Fig.  49  represents,  very  much 
reduced,  a  portion  of  the  lower  jaw  of  one  of  these  voracious  crea- 
tures, and  fig.  50  a  tooth  of  the  natural  size  of  another  species. 
The  limestone  in  which  they  are  found  also 
contains  particular  concretions  (fig.  51)  which 
are  considered  to  be  the  excrement  of  these 
animals,  and,  on  this  account,  called  coprolites, 
(from  the  Greek,  kopros,  dung,  and  lithos, 
stone).  The  family  of  squalae  was  then 
represented  by  the  division  of  cestra' dons, 
characterized  by  teeth 
adapted  for  grinding, 
(yz^.52);  and  by  that 
of  the  hybodons,  with 
conoidal  but  not  tren- 
chant teeth,  the  ena- 
mel of  which  is  plaited 
on  both  surfaces  (Jig. 
53).  The  true  sharks, 

Fig.  50.—  Tooth  of  the  with    teeth    flattened 
Megalichthys  Hibberti.    and  trenchar>t   on   tne 

edges,  (Jig.  54),  did  not  then  exist,  and  did  not  appear  until  very 
much  later  in  the  creta'ceous  formation. 

16.  Other  fishes  are  found  in  the  coal-basins  of  the  continent 
of  Europe,  either  in  the  bituminous  schists,  as  at  Sarrebruck  and 
at  Antun,  or  in  kidney-shaped  masses  of  carbonate  of  iron,  as  at 
Saint-Etienne.  They  belong  to  neighboring  genera  of  sturgeons, 
named  by  M.  Agassiz  palxoni'scus,  (Jig.  56),  and  am'blipterus, 
and  seem  to  have  lived  in  fresh  water. 

15.  What  animal  remains  are  found  in  the  coal-measures  ?     What  are 
coprolites  ? 

16.  Are  any  other  fishes  found  in  coal-beds  ? 


Fig.  51. — Coprolilf-s. 


COAL  FORMATION.  45 

17.  Marine  shells  are  rare  in  coal  strata,  and  are  only  found  in 
the  subordinate  limestone  of  Belgium  and  England ;  but  at  the 
same  time  there  were  some  species  of  unio  and  some  small  ento- 
mostracans  Avhich  indicate  at  least  an  afflux  of  fresh  water  to  the 
sea  at  the  points  where  these  particular  deposits  were  made. 


Fig.  52.—  Tooth  of  Fig.  53.— Tooth  of  Fig.  54.—  Tooth  of 

Ceslracion.  Hybodon.  true  Shark. 

18.  EXTENT  or  THE  COAL-MEASURES.     It  is  evident  that  the 
coal  formation  cannot  be  found  except  above  the  Cambrian,  Silurian 
and  Devonian  strata,  which  were  formed  anteriorly  to,  or  about  the 
time  of  these  deposites.     If  it  existed  before  that  period,  it  must 
be  necessarily  concealed  by  aU  the  strata  subsequently  formed,  and 
searches  have  been  extended  below  them  at  great  expense  for  this 
combustible.    The  consequence  is,  that  the  coal  formation  occupies  a 
small  portion  of  the  uncovered  surface  of  the  earth.     Ah1  the  depo- 
sites known  in  France  do  not  occupy  more  than  one  two-hundredth 
part  of  the  superficies  of  the  territory.     England  and  Belgium  are 
comparatively  richer,  for  in  the  first  the  surface  of  the  coal  forma- 
tion is  equal  to  one-twentieth  of  the  whole  kingdom,  and  in  the 
second  to  one  tAventy-fourth.     Ah1  the  other  States  of  Europe  are 
much  poorer,  and  some,  Sweden,  Norway,  Russia,  Italy  and  Greece, 
are  almost  entirely  without  this  valuable  formation.     Bohemia  is 
the  richest  part  of  Germany  in  coal,  although  it  does  not  produce 
largely.     The  northern  part  of  the  Spanish  peninsula  seems  to 
contain  considerable  deposites  of  coal,  and  to  participate,  in  this 
respect,  in  the  wealth  of  Western  Europe. 

19.  The  coal-fields  of  the  United  States  are  numerous  and  ex- 
tensive.    Coal  is  found  in  Massachusetts,  Rhode  Island,  Pennsyl- 
vania, Maryland,  Virginia,  Ohio,  Kentucky,  Tennessee,  Illinois, 
Alabama,  Mississippi,  and  Indiana ;  in  a  word,  the  coal  formation 
in  the  United  States  is  greater  than  in  any  country  or  kingdom  on 
the  face  of  the  earth,  and  embraces  every  variety  hitherto  disco- 
vered. 

20.  The  different  layers,  constituting  the  coal-measures,  were 
deposited  horizontally  at  the  bottom  of  the  basins  they  occupy,  but 
they  have  not  remained  in  this  position ;  at  certain  places  they 

17.  What  does  the  existence  of  the  genus  unio  in  the  coal-beds  indicate? 

18.  What  is  the  relative  geological  position  of  the  coal-measures? 

19.  In  what  parts  of  the  United  States  do  we  find  coal  ? 


46  COAL  FORMATION. 

were  raised  up,  and  at  others  lowered  down,  so  that  they  became 
more  or  less  oblique,  and  often  seem  to  be,  as  it  were,  folded  on 

themselves  ;  it  is  also  remarked  that 
frequently  a  certain  extent  of  the  mass 
formed  by  these  layers  has  been  sepa- 
rated from  neighboring  parts  by  a  sort 
of  split  or  cleft,  and  elevated  or  de- 
pressed to  a  different  level ;  conse- 
Fig.  55.— Fault.  quently  the  beds  of  coal  are  suddenly 

interrupted  at  these  points,  and  are 

found  further  on  at  a  different  height.     These  geological  accidents 
are  designated  by  miners  under  the  name  of  faults,  (Jig.  55). 

Speaking  of  the  origin  and  nature  of  coal,  Dr.  Buckland  remarks,  "  The 
most  early  stage  to  which  we  can  carry  b<ick  its  origin,  was  among  the 
swamps  and  forests  of  the  primeval  earth,  where  it  flourished  in  the  form 
of  gigantic  Ca'lamites,  and  stately  Lepidode'ndra,  and  Sigilla'rice.  From 
their  native  bed,  these  plants  were  transported  into  some  adjacent  lake,  or 
estuary,  or  sea.  .  Here  they  floated  on  the  waters,  until  they  sank  saturated 
to  the  bottom,  and  being  buried  in  the  detritus  of  adjacent  lands,  became 
transferred  to  a  new  estate  among  the  members  of  the  mineral  kingdom. 
A  long  interment  followed,  during  which  a  course  of  chemical  changes,  and 
new  combinations  of  their  vegetable  elements,  converted  them  to  the  mine- 
ral condition  of  coal.  By  the  elevating  force  of  subterranean  agency, 
these  beds  of  coal  have  been  uplifted  from  beneath  the  waters,  to  a  new 
position  in  the  hills  and  mountains,  where  they  are  accessible  to  the  industry 
of  man.  From  this  fourth  stage,  coal  has  been  removed  by  the  labours  of 
the  mirier,  assisted  by  the  arts  and  sciences,  that  have  co-operated  to  pro- 
duce the  steam-engine  and  the  safety-lamp.  Returned  once  more  to  the 
light  of  day,  and  a  second  time  committed  to  the  waters,  it  has,  by  the  aid 
of  navigation,  been  conveyed  to  the  scene  of  its  next  and  most  considerable 
change  by  fire ;  a  change  during  which  it  becomes  subservient  to  the  most 
important  wants  and  conveniences  of  man.  In  this  seventh  stage  of  its 
long  and  eventful  history,  it  seems,  to  the  vulgar  eye,  to  undergo  annihila- 
tion ;  its  elements  are,  indeed,  released  from  the  mineral  combinations 
which  they  have  maintained  for  ages,  but  their  apparent  destruction  is  only 
the  commencement  of  new  successions  of  change  and  of  activity.  Set  free 
from  their  long  imprisonment,  they  return  to  their  native  atmosphere,  from 
which  they  were  absorbed  by  the  primeval  vegetation  of  the  earth.  To- 
morrow they  may  contribute  to  the  substance  of  timber  in  the  trees  of  our 
existing  forests ;  and,  having  for  a  while  resumed  their  place  in  the  living 
vegetable  kingdom,  may,  ere  long,  be  applied  a  second  lime  to  the  use  and 
benefit  of  man.  And  when  decay  or  fire  shall  once  more  consign  them  to 
the  earth,  or  to  the  atmosphere,  the  same  elements  will  enter  on  some  fur- 
ther department  to  their  perpetual  ministration  in  the  economy  of  the  ma- 
terial world." 

21.  A  part  of  this  grand  upturning  of  the  coal  formation  has 
not  disturbed  the  more  recent  strata  by  which  it  may  be  covered, 
and  consequently  it  must  have  been  effected  at  the  close  of  the  geo- 
logical period  whose  history  we  have  just  studied. 

20.  How  were  the  coal-measures  deposited  ?     What  is  meant  by  a  Fault  ? 

21.  Has  the  disturbance  of  the  coal  strata  affected  the  strata  subsequently 
deposited  abcve  them  ? 


FOURTH  GEOLOGICAL  EPOCH.         47 

FOURTH  GEOLOGICAL  EPOCH. 

(Secondary  Formation  Continued.} 

Saliferous  Formation — New  Red  Sandstone — Po'ikilitic  (variegated)  group. 

22.  The  rich  vegetation  which  adorned  the  surface  of  the  earth 
during  the  coal  period,  seems  to  have  been  entirely  destroyed  or 
converted  into  coal,  by  the  geological  convulsion  which  separated 
this  epoch  from  the  succeeding  period ;  this  convulsion  was  fol- 
lowed by  the  formation  of  extensive  deposits  of  more  ancient  rocks 
and  sandy  matters,  as  well  as  by  the  effusion  of  different  rocks  of 
igneous  origin,  such  as  porphyries. 

23.  These  deposits,  which  are  indicative  of  great  movements 
in  the  waters,  constitute  the  formation  designated  by  geologists  under 
the  names  of  red  conglomerate,  new  red  sandstone,  rothe-todte- 
liegende,*  &c.     They  frequently  form  layers  six  hundred  feet  in 
thickness,  and  contain  scarcely  any  remains  of  organized  beings. 

24.  This  lower  new  red  sandstone,  or  penine  formation  of  the 
French,  is  very  abundant  in  Thuringia.     It  contains  very  few 
organic  remains.     Above  this  red  sandstone  we  find,  in  some  places, 
bituminous  schists,  which  are  very  remarkable,  especially  in  Thu- 
ringia, for  the  ores  of  copper  they  contain,  which  circumstance  has 
gained  for  them  the  name  of  kupfer-s chief er,  that  is,  copper-slate. 
They  contain  plants  which  appear  to  belong  to  the  family  of  algae, 
and  a  very  small  number  of  terrestrial  plants,  such  as  the  co'nifers. 
Higher  in  the  series  come  the  compact  limestones,  the  zechstein 
(mine-stone)  of  the  Germans,  separated  into  several  layers   by 
marls  ;  then  cellular  and  magnesian  limestones,  which  are  more  or 
Ises  friable,  and  again,  compact  limestone  and  argilla'ceous  matter. 
Such  is  the  assemblage  of  strata  in  Thuringia,  and  in  different 
parts  of  Germany  ;  but  in  England  the  whole  series  is  replaced  by 
the  magnesian  limestone. 

25.  It  was  about  this  geological  period  that  animals  belonging 
to  the  class  of  reptiles  were  created.     In  this  formation  we  find 
for  the  first  time  the  remains  of  sau'rians,  in  the  bituminous  schist 
and  in  the  zechstein,  and  subsequently  in  the  magnesian  limestone 
of  England.     These  reptiles  resemble  the  living  genera  of  the 
iguana  and  monitor.     We  also  find  fishes  of  the  genera  palxo- 
ni'scus  (Jig.  56  —  from  the  Greek,  palaios,  ancient,  and  oniskos, 

*  Rothe-todte-liegende — German  :  red,  dead,  lier ;  so  named  because  it  is 
of  a  red  colour,  underlies  the  metalliferous  strata,  and  is  dead,  or  worthless, 
as  far  as  any  metallic  produce  is  concerned. 

22.  What  became  of  the  plants  which  flourished  on  the  earth  previous  to 
the  time  of  the  coal  formation  ? 

23.  What  formation  is  next  above  the  coal  ? 

24.  What  are  the  characters  of  the  lower  new  red  sandstone  ?     What  is 
kupfer-schiefer  ? 

25.  What  animals  seem  to  belong  to  this  fourth  geological  epoch  ? 


48 


PALJEONISCUS.— PLATYSOMUS. 


a  kind  of  fish),  and  ambly'pterm,  (from  the  Greek,  amblus,  obtuse, 
and  pteron,  wing),  similar  to  those  of  the  coal-measures  ;  but  they 
are  not  found  in  any  formation  subsequent  to  that  we  are  now  con- 
sidering. 

The  palaoni'scus  is  found  in 
the  magnesian  limestone  of 
England  and  the  kupferzchiefer 
of  Germany.  The  head  is  of  a 
somewhat  singular  form,  espe- 
cially with  regard  to  the  ante- 
rior portion  of  the  face,  which 
forms  a  rounded  projection 
Fig.  5G.—Pal<B<mi  sous  above  and  beforc  the  upper  jaw? 

occasioned  hy  the  swelling  out  and  prolongation  of  some  of  the  bones  of  the 
skull.  The  orbit  of  the  eye  is  surrounded  by  a  series  of  small  narrow  bones, 
and  the  mouth  is  usually  large,  but  the  teeth  so  exceedingly  small  that  it  is 
rarely  possible  to  distinguish  them.  The  jaws,  however,  are  powerful,  and 
more  especially  the  lower  one,  which  is  larger  than  the  upper.  Ansted. 

The  genus  Platyso'mus 
(.fig-  57),  (from  the  Greek, 
platus,  flat,  and  soma,  body,) 
which  is  found  in  the  same 
strata,  differs  considerably 
from  the  palaeoni'scus,  as  the 
body  is  of  a  trapezoidal  form, 
is  much  raised,  and  nearly 
as  high  as  it  is  long,  while 
from  the  position  of  the 
scales  on  the  edge  of  the 

back  and  on  the  belly,  it  ap- 
Fig.  51.-Platyso  mus.  pearg  to  have  becn  fliten4 

r  The  head  is  large  in  proportion  to  the  size  of  the  body,  the  extremity  of 
the  snout  forms  a  slightly  rounded  projection,  the  mouth  is  small  and  nar- 
row, the  jaws  are  armed  with  small  but  very  pointed  teeth,  the  lower  jaw 
is  shorter  than  the  upper,  and  broader  in  proportion,  and  the  operculum  (or 
bony  scale  covering  the  gills)  is  narrow  and  much  elevated.  The  whole 
body  is  covered  with  large  scales. 

One  of  the  most  remarkable  peculiarities  in  the  structure  of  this  fish  is, 
that  although  the  body  is  flat,  short,  and  elevated,  like  that  of  the  recent 
flat-fish,  the  tail  instead  of  being,  as  in  the  latter,  much  forked  and  equally 
lobed — arrangements  which  appear,  in  the  present  state  of  things,  to  be  in- 
dispensable— retains  in  the  Platyso'mus  the  hc'tcrocercal  character,  the  upper 
portion  having  the  vertebral  column  continued  into  it,  and  being  mucfi 
longer  and  more  powerful  than  the  lower  portion,  which  rather  resembles  a 
small  accessory  fin.  Ansted. 

M.  Agassiz  classifies  fishes  according  to  the  form  of  their  scales.  All 
those  fishes  with  angular  scales  regularly  arranged  and  entirely  covering 
the  skin,  constitute  the  order  of  Ganoidcans  (from  the  Greek,  ganos,  splen- 
dour). The  order  of  Placoideans  (from  the  Greek,  plax,  a  broad  plate)  con- 
tains  fishes  whose  skin  is  covered  irregularly  with  plates  of  enamel,  often 
of  considerable  dimensions,  but  sometimes  reduced  to  small  points,  like  the 
shagreen  on  the  skin  of  the  shark,  and  the  prickly  tubercles  of  the  ray. 
The  order  of  Ct.enoideans  (from  the  Greek,  kteis,  in  the  genitive  ktcnos,  a 
comb)  is  characterized  by  horny  or  bony  scales,  jagged  like  the  teeth  of  a 


TRIASSI(T  SYSTEM.  49 


comb  on  the  outer  edge.  The  perch,  and  many  other  existing  genera,  are 
of  this  order,  which  contains  but  few  fossil  forms.  The  order  of  Cyclodi- 
ans  (from  the  Greek,  kuklos,  a  circle)  is  characterized  by  having  scales 
which  are  smooth  and  simple  at  the  margin,  as  in  the  herring,  salmon,  &c. 
When  the  vertebral  column  is  prolonged  into  the  caudal  fin,  the  tail  is 
he'terocercal ;  when  the  vertebral  column  terminates  where  the  tail  is  given 
off,  we  have  the  homocercal  tail,  as  in  most  of  the  recent  fishes. 


In  this  same  formation  we  also  find  Spi'rifers  (fig.  58),  and 
Productus  (figs.  59, 00),  and  especially  the  Productus  aculea'tus 
(fig.  59),  which,  under  the  name  of  gry'phites  aculedtm^  has 
been  regarded  as  characteristic  of  it  in  Germany ;  and  sometimes, 
in  consequence,  the  zechstein  is  called  gryphitcnkalk,  which,  on 
this  account,  has  been  confounded  with  the  lias.  Other  mollusks, 
as  well  as  the  remains  of  encri'nites,  which  seem  to  be  the  same  as 
those  of  the  carboni'ferous  limestone,  are  also  found. 


Fig.  58.— Spi'rifer  Fig.  59.— Productus         Fig.  GO.— Pro- 

undula'tus.  aculea'tus.  ductus  calvus. 

26.  Next  in  order  is  a  layer,  known  as  the  sandstone  of  Vosges, 
which  lies  either  on  the  red  sandstone  or  magnesian  limestone ; 
or,  when  these  strata  are  wanting,  on  some  other  more  ancient  rock. 
After  the  formation  of  the  several  portions  of  the  crust  of  the  globe 
just  mentioned,  geological  convulsions  again  occurred,  and,  as  it 
appears,  the  mountains  of  Vosges,  the  Black  Forest,  &c.,  were 
elevated  about  the  same  time.     After  this  movement,  new  deposits 
were  formed  around  the  base  of  the  hills,  constituting  the  Trias 
System  of  French  and  German  geologists,  so  named  because  it  is 
composed  of  three  kinds  of  rocks. 

27.  The  TRIAS  or  TRIA'SSIC  SYSTEM  (or  upper  new  red  sand- 
stone of  the  English)  consists  of: — 

1 .  Bunter  Sandstein,  (gres  bigarre  of  the  French),  a  quartzose 
sandy  deposit,  which  usually  forms  the  base  of  the  system,  both  in 
France  and  Germany. 

2.  Muschelkalk,  (shell-chalk),  a  well-marked  and  highly  fossili'- 
ferous  limestone,  rarely  absent  in  the  continental  series,  but  never 
found  in  England. 

3.  Keuper,  a  singular   group  of  sandy  marls,  of  variegated 
colours,  frequently  containing  salt  and  gypsum,  and  remarkable 
for  numerous  fossil  vegetable  remains. 

28.  The  BUNTER  SANDSTEIN,  or  Gres  Bigarre,  is  a  fine-grained, 

26.  What  is  the  relative  position  of  the  Vosges  sandstone  ? 

27.  What  is  the  trias,  or  tria'ssic  system  ? 

5 


50 


BUNTER  SANDSTEIN. 


.  61.— Bird-tracks. 


solid  sandstone,  sometimes  white,  but  more  frequently  of  a  red, 
blue,  or  greenish  tint.  The  structure  of  the  lower  part  is  tolerably 
close-grained,  and  sufficiently  compact  to  form  a  good  building 

stone ;  but  the  uppermost  strata  are 
fissile  and  incoherent,  and  pass  into 
an  earthy  clay  containing  gypsum 
(plaster  of  Paris).  The  intermedi- 
ate portion  is  compact,  like  the 
lower,  but  its  structure  is  that  of 
a  conglomerate,  and  is  used  for  mak- 
ing millstones.  In  many  districts  the 
Bunter  sandstein  contains  numerous 
remains  of  fossil  plants  and  marine 
shells,  but  the  latter  are  rare  and  con- 
fined to  particular  localities.  In  this 
series  are  found  foot-prints,  (fig.  61 ), 
some  of  which  evidently  belonged  to 
birds,  and  others,  according  to  the 
opinion  of  certain  naturalists,  belonged 
to  marsupial  mammals,  or  gigantic 
batrachian  reptiles. 

29.  The  sandstones  and  marls  of  this  part  of  the  series   are 
spread  over  an  extensive  tract  of  land  in  western  Europe,  more 
particularly  in  France,  and  in  south-western  and  central  Germany. 
On  the  right  bank  of  the  Rhine,  in  Swabia,  there  are  some  dis- 
tricts in  which  the  bunter-sandstein  rests  immediately  on  the  rothe- 
todte-liegende,  the  lower  new  red  sandstone  (Vosges  sandstone) 
being  absent,  and  no  other  representative  of  the  magnesian  lime- 
stone taking  its  place. 

30.  The  MUSCHELKALK  (also  called  conchylian  limestone,  shell- 
limestone)  is  a  compact  limestone  of  a  grey  or  greenish-grey  co- 
lour, and  commonly  contains,  in  great  abundance,  the  remains  of 
shells  and  fragments  of  radiated  animals  and  fishes.     Sometimes 
the  muschelkalk  is  a  bituminous  rock,  and  emits  a  fetid,  disagreea- 
ble odour  when  rubbed  or  struck  with  a  hammer. 

31.  Among  the  characteristic  shells  are  the  tfmmoni'tes  nodo'sus 
(fig.  62) ;  Ji'vi'mla  socia'lis  (fig.  63).  Possido'nia  minu'ta  (fig. 
64).     In  this  stratum  the  Trigo'nia  ( fig.  65)  is  first  met  with,  and 
species  of  it  are  found  extending  through  various  subsequently- 
formed  strata  to  the  chalk.     A  great  many  Encri'nitcs  are  also 
found,  especially  the  species  monilifo' rmis  (fig-  66). 

28.  What  is  Bunter  Sandstein  ?     What  animal  remains  do  we  find  in  the 
Bunter  Sandstein  ? 

29.  Where  is  the  Bunter  Sandstein  met  with? 

30.  What  is  Muschel-kalk  ? 

31.  What  shells  are  characteristic  of  the  Muschel-kalk  ?     What  are  Am- 
monites  ? 


AMMONITES. 


51 


The  Ammonites,  (Jig.  62),  or  Co'rnua  Ammonis — so  called  from  a  sup- 
posed resemblance  to  the  horns  engraven  on  the  heads  of  Jupiter  Ammon — 
are  among  the  most  common  and  well-known  fossils.  Local  legends, 
ascribing  their  origin  to  swarms 
of  snakes  turned  into  stone  by 
the  prayers  of  some  patron  saint, 
are  still  extant  in  certain  parts 
of  England,  and  perpetuated  by 
the  name  of  snake-stones,  by 
which  these  fossils  are  provin-  v 
cially  known.  Several  hundred 
species  have  been  described ; 
they  are  divided  into  genera, 
which  are  characterized  by  es- 
sential modifications  in  the  di- 
rection of  the  spire,  and  the 
inflections  of  the  septa. 

The  shell  of  the  ammonite  is  Fi     QO.— Ammonites  nodosus. 

generally  thinner  and  more  deli- 
cate than  that  of  the  nautilus,  (to  which  it  bears  considerable  resemblance), 
and  in  some  species  it  resembles  the  flexible  covering  of  the  argonaut;  pos- 
sibly, in  these  species  the  animal,  like  the  recent  paper  nautilus,  may  have 
possessed  a  pair  of  arms  terminating  in  broad  membranous  expansions, 
which  secreted  the  shell,  and  generally  remained  in  contact  with  it;  other- 
wise it  is  difficult  to  explain  how  such  delicate  fabrics  should  have  been 
uninjured. 

The  living  and  extinct  species  of  testaceous  cephalopods,  "  are  all  con- 
nected by  one  plan  of  organization  ;  each  forming  a  link  in  the  common 
chain  which  unites  the  existing  species  with  those  that  prevailed  among  the 
earliest  conditions  of  life  upon  our  globe,  and  all  attesting  the  identity  of 
the  design  that  has  effected  so  many  similar  ends,  through  such  a  variety 
of  instruments,  the  principle  of  whose  construction  is,  in  every  species,  fun- 
damentally the  same. 

"  Throughout  the  various  living  and  extinct  genera  of  these  beings,  the 
use  of  the  air-chambers  and  siphon  of  their  shells,  to  adjust  the  specific 
gravity  of  the  animals  in  rising  and  sinking,  appears  to  have  been  identical. 
The  addition  of  a  new  transverse  plate  within  the  coiled  shell  added  a  new 
air-chamber,  larger  than  the  preceding  one,  to  counterbalance  the  increase 
of  weight  that  attended  the  growth  of  the  shell  and  body  of  these  ani- 
mals."— Buckland. 

The  occurrence  of  the  nautilus  and  its  congeners  among  the  earliest 
traces  of  the  animal  kingdom,  and  their  continuance  throughout  the  im- 
mense periods  during  which  the  family  of  ammonites  was  created,  flour- 
ished, and  became  extinct,  and  the  existence  of  species  of  the  same  genus 
at  the  present  time,  are  facts  too  remarkable  to  have  escaped  notice.  To 
these  facts  Mrs.  Howitt  alludes  in  the  following  lines  to  the  nautilus  : 

"Thou  didst  laugh  at  sun  and  breeze 
In  the  new  created  seas;   ' 
Thou  wast  with  the  reptile  broods 
In  the  old  sea  solitudes, 
Sailing  in  the  new-made  light, 
With  thecurled-up  ammonite. 
Thou  surviv'dst  the  awful  shock, 
Which  turn'd  the  ocean-bed  to  rock, 
And  changed  its  myriad  living  swarms. 
To  the  marble's  veined  forms." 

See  Mantell's  Medals  of  Creation. 


52       AVICULA.— POSIDONIA— TRIGONIA— ENCRINITES. 


The  genus  A'vicula  (Jig.  63)  belongs  to  the 
division  of  bivalve  shells,  and  the  fossil  species, 
a  great  many  of  which  are  known,  resemble  the 
pearl  oyster  (A'vicula  Margaritifera). 


The  genus  Posido'nia,  (Jig.  64),  (from 
Greek,  poseidon,  Neptune),  also  belongs  to 
bivalves,  and  is  found  in  the  lower  part  of  thu 
carboni'ferous  series. 


the 
the 


Fig-  65. —  Trigo'nia  vulga'ris. 

The  genus  Trigonia,(Jig.65 — from  the  Greek,  trigonos,  three-cornered), 
belongs  to  the  family  of  ostracea ;  the  only  living  species  known  inhabits 
the  seas  of  New  Holland. 


Fig.  66. — Encri'nites  monilifor'mis. 

The  Encri'iiites,  (Jig.  66 — from  the  Greek,  kiinon,  a  lily),  belong  to  the 
family  of  Echi'noderms.  The  skeleton  of  this  animal  is  said  to  consist 
of  not  less  than  26,000  separate  pieces.  The  body  of  the  lily-encrinite  was 
supported  on  a  long  and  nearly  cylindrical  column,  attached  to  a  rock  or 
some  hard  substance  at  the  bottom  of  the  sea  by  an  enlargement  of  its  base. 
This  column  was  made  up  of  a  vast  number  of  joints,  through  which  was 
an  aperture,  descending  from  the  stomach  of  the  animal  to  the  base  of  the 
column. 

32.  The  KEU'PER  (a  German  word)  is  the  name  given  to 
the  uppermost  division  of  the  tria'ssic  system,  and  is  often  ap- 
plied to  the  upper  part  of  the  new  red  sandstone  formation.  This 


32.  What  are  the  characters  of  the  Keuper  formation  ?     What  organic 
remains  are  found  in  the  Keuper  series  ? 


KEUPER  FORMATION. 


53 


group  usually  consists  of  a  numerous  series  of  mottled  marls,  of  a 
red,  greenish  grey,  or  blue  colour,  which  pass  into  green  marls, 
black  slaty  clays,  and  fine-grained  sandstones.  Throughout  the 
series,  common  rock-salt  and  gypsum  are  abundant,  but  the 
organic  remains  of  animals  are  extremely  rare.  Of  plants,  how- 
ever, a  considerable  number  are  preserved  in  some  localities  ;  and 


Fig:  67. —  Volt'zia  hetcro'phylla. 

these  indicate  a  wide  departure  from  the  carboniferous  period,  and, 
as  well  as  the  shells,  seem  to 
possess  more  analogies  with  the 
forms  of  life  determined  from  the 
fossils  of  the  secondary  period,  than 
with  those  common  in  palae'ozoic 
rocks.  Besides  peculiar  species 
of  ferns,  the  trias  presents  us  with 
fossil  plants  not  previously  met 
with.  In  the  sandstone  are  par- 
ticular species  of  co'nifers  which 
constitute  the  genus  Volt'zia,  (fig. 
67),  and  in  the  limestone,  remains 
of  cyc'adese  of  the  genus  mantellia; 
this  last  family  is  very  abundant 
in  the  Keuper,  in  which  are  found 
the  genus  Nilso'nia,  and  the  genus 
PterophyUum,(Jig.  68).  Several 
species  of  large  saurian  reptiles 
are  also  found  in  the  trias  group 
of  rocks.  Fig.bS.—PCe'rophyllumPkininge'rii. 


5* 


54  LIAS,  OR  LIASSIC  SYSTEM. 

FIFTH  GEOLOGICAL  EPOCH. 

Lias,  or  Lia'ssic  System — Jura'ssic  Formation — O'olilic  System. 
(Secondary  Formation  Continued.) 

33.  Up  to  this  period  of  its  geological  history,  we  have  seen  the 
earth  was  inhabited  only  by  plants,  some  inferior  animals,  such  as 
zo'ophytes,  mollusks  and  fishes,  and  lastly,  by  some  reptiles.     Dur- 
ing the  period  at  which  we  have  now  arrived,  this  state  of  things 
changed,  and  there  Avas  created  a  new  fauna  composed  of  most 
remarkable  animals,  characterized  especially  by  a  multitude  of 
reptiles,  of  strange  form  and  gigantic  size. 

34.  The  formation  of  the  LIAS — so  called  from  a  barbarous  pro- 
vincial word,  supposed  to  be  a  corruption  of  layers,  and  to  allude 
to  the  riband-like  appearance  of  the  rock  when  seen  in  section — 
the  Lias  consists  of  strata,  in  which  an  argilla'ceous  character  pre- 
dominates throughout,  but  which  are  also  remarkable  for  a  quan- 
tity of  calcareous  matter   mingled  with  the   clay,  and   forming 
occasional  bands  of  argilla'ceous  limestone.     A  few  beds  of  sand- 
stone also  alternate  with  the  clay  and  marl,  and  are  sometimes 
mixed  with  the  latter,  forming  a  marly  sandstone  of  a  white  or 
greenish  colour. 

35.  The  inferior  layers  of  the  lia'ssic  system  are  characterized, 
according  to  M.  Leymerie,  by  the  presence  of  the  Pecten  lugdu- 
ne'nsis  (Jig-  69),  and  different  species  of  echi'nidae  of  the  division 
diade'ma  (fig.  70). 


Fig.  69. — Pe'cten  lugdune'nsis.  Fig.  70. — Diade'ma  seria'le. 

36.  The  middle  layers,  or  the  lias  proper,  are  distinguished 
especially  by  the  presence  of  the  Gry'phea  arcudta,  (fig.  71),  and 
the  ammonite  named  after  Dr.  Buckland,  (fig.  72),  the  spi'rifer  of 

33.  What  is  remarked  of  the  animals  in  the  early  geological  periods  ? 

34.  Of  what  is  the  Lias  formation  constituted  ? 

35.  What  animal  remains  characterize  the  inferior  beds  of  the  Lias  ? 
3G.  How  is  the  Lias  proper  characterized  ? 


FOSSILS  OF  LIASSIC  SYSTEM. 


55 


Walcot,  (Jig.  73),  the  last  of  the  race,  the  giant  plagio'stoma,  (Jig. 
75),  and  the  spinous  plica  tula,  (Jig.  74). 


Fig.  71. — Gry'phea  arena  ta. 


Fig.  72.— Ammonites  Buckla'ndii. 


Fig.13. — Spi'rifer  Walcoti. 


Fig.lt.— Plica' tula  Spino'sa. 


Fig.  75. — Plagio'stoma  giga'nteum. 


37.  The  superior  part  of  the  lias  contains  a  great  number  of 
belemnites,  (Jigs.  76,  77),  the  ammonite  named  after  Walcot,  (fig. 
78),  and  an  a'vicula  with  unequal  valves,  (Jig.  79),  &c. 


Fig.  76. — Bele'mnites  pistillifo'rmis. 


Fig.  77.— Bele'mnites  Sulca'tus. 


37.  What  fossils  belong  to  the  upper  part  of  the  Lias  ? 


56 


FOSSILS  OF  LIASSIC  SYSTEM. 


. — A'vicula  in- 
tBquiva'lvis. 


Fig.  78. — Ammonites  Walcoti. 

38.  We  also  find  in  this  group  various  species  of  Trigo'nia, 
(fig.  80),  which  appear  to  have  existed  in  all  parts  of  the  depo- 
sit ;  but  the  species,  which  perhaps  furnish  very  important  charac- 
teristics, have  not  yet  been  studied  sufficiently  in  relation  to  the 
grouping.  They  extend  through  the  o'olitic  series  to  the  chalk 
formation. 


Fig.  SQ.—  7rigo'Tiia  clavella'ta. 

39.  We  find  too,  in  the  lias  for  the  first  time,  in  ascending 
through  the  crust  of  the  earth,  those  singular  saurians  whose  ske- 
leton at  the  same  time  reminds  us  of  lizards,  crocodiles,  fishes  and 
mammals ;  their  feet,  which  are  in  form  of  paddles,  show  they 
were  aquatic  in  their  habits :  such  are  the  Ich'thyosau'rus,  (fig> 
81),  some  of  which  were  twenty-five  feet  in  length;  the  Plei'sio- 
sau'rus,  (fig.  82),  some  species  of  which  are  nearly  fifteen  feet 
long. 

38.  Are  any  species  of  Trigo'nia  characteristic  of  any  part  of  the  Lias  ? 

39.  What  is  an  Ich'thyosau'rus  ?     What  is  the  lowest  stratum  in  which  it 
is  found  ?     What  is  the  Plei'siosau'rus  ? 


FOSSILS  OF  LIASSIC  SYSTEM.  57 

The  I'CHTIIYOSAU'RUS  (from  the  Greek  ichthus,  a  fish,  and  sauros,  a  lizard 
—fish-lizard— Jig.  81),  must  have  resembled  some  huge  fish,  having  an 
exceedingly  large  head  and  very  powerful  tail.  The  spine  consisted  of  120 


Fig.  81. — I'chtliyosau'rus  communis. 

vertebrse  or  joints,  besides  those  of  the  neck,  which  were  united  into  a  mass 
of  solid  bone.  The  eye  was  an  extremely  powerful  organ,  "  capable  of 
adapting  itself,"  says  Dr.  Buckland,  "to  great  changes  of  distance,  and 
great  alterations  in  the  amount  of  light  in  which  it  could  be  used ;  giving 
to  its  possessor  the  power  of  discerning  a  far-distant  object,  as  well  as  one 
near  at  hand,  and  of  pursuing  its  prey  in  the  darkness  of  night,  or  the  dim 
obscurity  of  the  depths  of  the  ocean,  as  well  as  in  the  day-time  or  on  land." 
This  animal  had  a  wrinkled  skin,  like  the  whale,  without  scales. 


Fig.  S2. — Plei'siosau'rus  dolichodeirus. 

The  PLEI'SIOSAU'RUS  (from  the  Greek  plesion,  near,  and  sauros,  a  lizard  or 
reptile — resembling  a  reptile— -Jig.  82)  may  be  described  as  exhibiting  the 
head  of  a  lizard,  attached  to  a  neck  whose  length  was  three,  or,  in  some 
species,  even  more  than  four  times  that  of  the  head.  The  body  appended 
to  this  head  and  neck  was  comparatively  small  and  fish-like ;  the  extremities 
were  large  paddles,  and  the  tail  like  that  of  the  crocodile.  The  neck  con- 
sisted  of  upwards  of  thirty  vertebrae  or  joints,  and  was  very  long  and  flex- 
ible. Ansted. 


Fig.  83. — Pteroda  'ctylus  longiro'stris. 

40.  We  also  find,  for  the  first  time,  in  the  lia'ssic  group,  the 
pterodac'lylus  (from  the  Greek  pteron,  wing,  and  daklulos,  finger-— 


58  JURASSIC  OR  OOLITIC  SYSTEM. 

fig. 83),  a  flying  saurian,  whose  head  and  neck  gave  it  the  semblance 
of  a  bird,  and  its  tail  was  like  that  of  a  mammal,  while  its  extremities 
were  analogous  to  those  of  a  bat ;  it  was  capable  of  walking  and 
flying,  and,  perhaps,  of  climbing  steep  rocks  in  pursuit  of  food. 

41.  With  the  remains  of  these  singular  animals  are  found,  in  the 
lias  of  Lime-Regis,  on  the  coast  of  Dorset,  England,  an  immense 
quantity  of  coprolites  (from  the  Greek  kopros,  dung,  and  lithos, 
stone),  which  probably  belonged  to  them :  sometimes  their  intes- 
tines are  found  in  their  skeletons  ;  and  we  also  find,  in  these,  the 
remains  of  fishes   and   other  reptiles,  clearly  showing  how  the 
aquatic  species  were  nourished.     The  remains  of  insects  are  found 
with  those  of  the  pteroda'ctyli  at  Solenhofen,  in  Franconia,  also 
showing  what  was  the  food  of  these  animals. 

42.  Saurians  resembling  crocodiles  were  much  less  abundant  in 
this  epoch,  although  we  find,  in  the  lias,  remains  which  prove 
their  existence.   The  me'galosau'rus  (from  the  Greek  me  gas,  great, 
and  sauros,  reptile)  partook  of  the  nature  of  the  crocodile  and 
monitor,  and  must  have  been  from  fifty  to  sixty  feet  in  length. 

43.  Ink-bags  of  considerable  size  (Jig.  84),  ana- 
logous to  those  of  the  cuttle-fish,  are  also  found.     In 
the  lias  of  Lime-Regis,  the  dorsal  bones  of  the  calmar 
are  also  met,  with  other  traces  of  this  genus,  as  well 
as  of  belemni'tes.     The  ink  or  se'pia,  which  may  be 
obtained  from  these  fossils,  is  as  good   as  that   pre- 
pared from  the  recent  cuttle-fish,  and  has  been  used. 

44.  THE  JURA/SSIC  OR  O'OLITIC  SYSTEM. — O'olite 
(from  the  Greek  don,  an  egg,  and  lithos,  a  stone),  is  a 
granular  variety  of  carbonate  of  lime,  frequently  called 
roe-stone,  from  its  resemblance  to  a  fish-roe,  or  egg-bag. 
The  frequency  of  the  occurrence  of  this  particular 

.. — Ink-  /•    i-  •  •  ^    i  •         i 

bag.          form  of  limestone  in  a  great  series  of  deposits,  has 
caused  the  name  of  o'olitic  to  be  applied  to  the  whole  series. 

45.  The  o'olitic  or  jura'ssic  deposits  (the  Jura-kalk  of  German 
geologists),  are  divided  into  several  groups,  which  are  distinguisha- 
ble from  each  other  by  their  relative  position  in  the  scale  of  eleva- 
tion, but  more  particularly  by  the  fossils  found  in  them ;  the  re- 
mains which  are  characteristic  of  the  preceding  groups,  are  not 
met  with  in  this.    The  o'olite  is  divided  into  the  lower,  middle,  and 
upper  o'olites. 

46.  The  lower  o'olite,  the  first  in  the  series  of  o'olitic  deposits, 

40.  What  is  a  Pteroda'ctylus  ?     Where  is  it  found  ? 

41.  What  was,  probably,  the  food  of  the  Pteroda'ctylus  ? 

42.  What  was  the  Me'galosau'rus  ? 

43.  What  other  fossil  substances  are  found  in  lias  ? 

44.  What  is  o'olite  ? 

45.  How  is  the  o'olitic  system  divided  ?    How  are  the  divisions  recognised  ? 

46.  Of  what  does  the  lower  o'olite  consist?     By  what  fossil  is  it  charac- 
terized ? 


FOSSILS  OF  THE  OOLITE. 


59 


consists  at  first  of  layers  of  marl  intermixed  with  sand,  then  layers 
of  ferru'ginous  o'olites,  and  strata  of  compact  limestone  and  clays, 
more  or  less  pure  and  fitted  for  the  purposes  of  the  fuller,  and 
hence  named/w//ers'  earth.  The  first  of  these  marly  deposits  joins 
with  the  marls  of  the  lias,  but  is  characterized  by  a  new  species  of 
gryphae'a  (Jig.  85),  which  is  not  found  in  the  preceding  layers. 

47.  Above   these   deposits 
are  found  fissile  marls,  lime- 
stone, with  ferru'ginous  o'olite ; 
to  which  succeed  earthy  de- 
posits, the  great  o'olite,  which 
consists  of  a  variable  series  of 
coarse    shelly   limestone   (lo- 
cally called  "rag"),  alternat- 
ing with  beds  of  fine  soft  free- 
stone, devoid   of  fossils,   and 
admirably  adapted  for  building 
purposes.    Above  these  again 
come  marls,  sands,  clays,  and 
limestones,  some  of  which  are 
full  of  shells.  They  are  known 
under  the  names  of  Bradford 
day,  Forest  marble,  and  Corn- 
brash.     In  spite  of  the  num- 
ber of  fossils,  often  broken  and 
in  the  state  of  moulds,  found 
in  this  group,  it  is  difficult  to 
designate  those  which  are  cer- 
tainly characteristic  of  it.  Fig.  85.—Grypha'a  cym'frium. 

48.  To  the  Gryphae'a  cym'bium  (Jig.  85),  which  is  characteristic 
of  the  first  group  of  the  o'olitic  deposit,  and  forming,  as  it  were,  a 
new  geognostic  horizon,  we  may  add  the  O'strea  acumina'ta  (Jig.  86), 


Fig.  87. —  Terelra'tula  digo'na. 


Fig.  86. — O'strea  acumina'ta. 


47.  What  is  found  above  the  lower  o'olite  ? 


60  FOSSILS  OF  THE  OOLITE. 

which  is  found  in  the  upper  marls,  or  limestones  sometimes  met 
with  in  their  place :  different  species  of  Terebra'tula  (Jigs.  88, 89), 


—  Terebrat.globa'ta.  FigSQ.—  Tereb.  spino'sa.  Fig.QQ.  —  Ammonites  Brongnia'  rtii. 


which  seem  to  belong  more  particularly  to  the  lower  o'olite,  as  well 
as  a  small  globose  species  of  ammonites  (fig.  90). 

49.  In  the  limestones   proper,  different  species  of  ammonites 
(fig.  91)  are  found;  various  species  of  pleurotoma'ria  (fig.  92), 


Fig.  91. — Ammonites  stria' lulus.         Fig.  92. — Pleuroloma'ria  cono'idea. 

which  seem  to  be  characteristic,  and  a  great  number  of  shells  of 
divers  kinds,  are  met  with.  Encrini'tes,  frequently  very  nume- 
rous, which  are  chiefly  referred  to  the  pyriform  species,  apiocri'- 
nites,  are  sometimes  found  on  the  very  spot  where  they  lived, 
attached  to  the  solid  materials  forming  the  bottom  of  the  sea  of  that 
epoch,  and  covered  by  successive  deposits  of  the  earthy  matter  of 
which  it  was  constituted. 

50.  An  important  fact  is  connected  with  the  marls  and  fissile 
limestones  which  form  the  first  of  the  o'olite  system :  the  first,  or 
most  ancient  fossil  mammals,  were  discovered  in  Stonefield  slates. 

48.  What  fossils  are  characteristic  of  the  o'olite  ? 

49.  What  fossils  are  found  in  the  limestone  proper  of  the  o'olite  scries  ? 

50.  What  important  fact  is  connected  with  the  fissile  limestone  and  marls 
of  the  lower  o'olite  ? 


FOSSILS  OF  THE  O'OLITE. 


61 


These  small  ani- 
mals, the  lower 
jaw  of  one  of 
which  is  repre- 
sented (fig.  93), 
belong  to  the  mar- 
supials ;  that  is, 
one  of  the  most 
imperfect  orders 

Of    the    Class. Fig.W.—JawoftheDide'lph 

Bones  of  large  animals,  thought 
to  belong  to  the  order  of  ceta' 
cea,  are  also  found  in  the  o'oli- 
tic  strata. 

51.  Con'ifers,  which  are  but 
rarely  found  beyond  the  shell- 
limestones,  are  abundantly 
met  with  in  the  o'olite  series, 
of  particular  genera  (Jig.  94), 
with  Cyca'dete  (Jig.  95)  — 
ferns  of  different  species,  dif- 
fering from  all  those  met  in 
more  ancient  strata,  and  finally 
a  true  equisetum  (fig.  96). 


\  Buckla'ndii — (twice  the  natural  size'). 


Fig.95. — Ptero 'pJiyllum  Williamso'nis. 


51.  What  fossil  plants  are  found  in  the  lower  o'olite  ? 
6 


62 


FOSSILS  OF  THE  O'OLITE. 


52.  MIDDLE  O'OLITE. — This  group,  which  is  less  complicated 
than  the  preceding,  at  the  lowest  part  consists  of  clay,  called  Oxford 
clay,  with  layers  of  calcareous  grit,  and  stratoid  masses  of  lime- 
stone. Above  these  are  found  sands,  and  limestones  which  are 
more  or  less  o'olitic,  and  often  ferru'ginous.  In  this  group  we  find 
deposits  of  o'olitic  iron,  which  had  already  appeared  in  the  pre- 
ceding series.  It  is  very  rich  in  fossils,  particularly  ammonites ; 
and  the  Jinanchy'tes  bicorda'tus  (fig.  97)  is  very  common. 


Fig.  97. — Ananchy'tes  licorda'lus. 

Ananchy'tes  is  a  genus  of  the  family  of  Echini'dese,  or  sea-urchins,  some- 
times vulgarly  called  sea-eggs.  The  family  contains  thirteen  genera,  which 
are  distinguished  from  each  other  by  the  form  and  size  of  the  ambula'cra, 
(alleys) — the  narrow  longitudinal  portions  of  the  shell  of  the  echinus  or  sea- 
urchin,  which  are  perforated  with  a  number  of  small  orifices,  giving  pas- 
sage to  tentacular  suckers,  and  alternate  with  the  broad  tuberculate  spine- 
bearing  portions  (see  Jig.  70) — and  also  by  the  position  of  the  vent,  and  of 
the  mouth.  Figure  70,  p.  54,  exhibits  the  ambula'cra,  between  the  tubercles 
to  which  the  spines  are  attached  in  living  species. 

53.  What  especially  characterizes  the  Oxford  clays  is  the  pre- 
sence, often  in  abundance,  of  a  new  species  of  Grypnae'a  (Jig-  98), 


Fig.  98.  Gryplia'a  dilata'ta.    Fig.  99.  0' street  Ma'rskii.    Fig.  101,  Tcrebra'tula  impre'ssa. 

the  O'strea  Ma'rshii  (fig.  99),  which  already  commenced  in  the 
preceding  group,  a  great  number  of  different  terebra'tula,  among 

52.  Of  what  does  the  middle  o'olite  consist  ?     What  fossils  belong  to  it? 

53.  How  are  the  Oxford  clays  especially  characterized  ? 


FOSSILS  OF  THE  O'OLITE. 


63 


which  we  find  in  the  upper  part  of  the  series,  the  Terebra'tula 
Thurmanni  (Jig.  100),  and  the  Terebra'tula  impressa  (fig.  101). 
The  moulds  of  these  shells  are  frequently  silicious,  and  we  find, 
in  the  upper  layers,  beds  of  silicious  balls  of  loose  texture,  some- 
times enclosing  silicious  moulds  of  shells. 

54.  The  upper  group  of  the  middle  o'olite,  called  coral  o'olite, 
consists  almost  entirely  of  limestone ;  it  is  divided  into  different 
thick  layers,  which  are  distinguishable  from  each  other  by  their 
structure.    The  first  or  lowest  layers  are  ordinarily  compact,  grey- 
ish or  yellowish,  filled  with  polypa'ria  or  corals  of  a  sac'charoid 
structure,  or  those  which  have  passed  to  the  silicious  state :   this 
constitutes  the  coral  rag  of  English   geologists.      Some   of  the 
succeeding  layers  are  o'olitic,  frequently  of  large  irregular  grains, 
mingled  with  fragments  of  rolled  shells  ;  others  are  compact,  pass- 
ing into  chalk  or  even  marl  of  greater  or  less  solidity. 

55.  The  numerous  polypa'ria  contained  in  this  group  present 
to  us  caryophy'llia  (fig.  21),  a'strea,  meandri'na,  madrepores  of  a 
great  number  of  species,  resembling  more  or  less  those  of  coral 
reefs,  and  a  great  many  other  genera.     Among  the  shells,  ammo- 
nites are  less  common ;  but  above  the  o'olite,  where  all  the  organic 
remains  are  broken,  the  lowest  layers  contain  a  great  quantity  of 
various  shells,  among  which  are  neri'nea  (figs.  102,  103).     The 


Fig.  102.— Neri'nea  Goodhallii. 


Interior  of  the  shell,  showing  the 

plic&  of  its  colum'nella.  fig.  103. — Neri'nea  mosa. 

superior  strata  contain  a  great  quantity  of  astarles  (figs.  104, 
105),  the  most  characteristic  of  which  is  the  astarte  minima. 

54.  What  are  the  characters  of  the  upper  group  of  the  middle  o'olite  ? 


What  is  coral 


rag 


55.  What  genera  of  corals  are  found  in  the  middle  o'olitc  ?     What  fossil 
Shells  do  we  find  in  this  group  ? 


64 


FOSSILS  OF  THE  O'OLITE. 


Fig.  104. — Astartemi'nima.  Fig.  105. — Astarte  elegans. 

Among  other  shells,  we  may  cite  the  Dicefras  arieti'na 

106) ;    and    among    the  echi'noderms,    the    cida'ris    corona'ta 
(fig- 


Fig.  106.— Mould  and  shell  of  the  Dice 'r as 
arieti'na. 


Fig.  101.— Cida'ris 
corona'ta. 


56.  UPPER  O'OLITE. — This  group  is  divided  into  Kimmeridge 
clay,  and  Portland  o'olite.     Kimmeridge  clay,  (so  named  because 
it  is  well  exhibited  at  Kimmeridge  Bay,  and  near  the  village  of 
the  same  name,  in  the  isle  of  Purbeck \,  is  of  a  blue,  slaty,  or  grey- 
ish yellow  colour.     Above  this  is  the  Portland  stone,  which,  with 
alternations  of  compact,  marly,  sandy  or  o'olitic  limestones,  termi- 
nates the  Jura'ssic  or  o'olitic  system. 

57.  The  organic  remains  which  characterize  this  group  are  of 
the  genera  ostrea,  and  ex'ogy'ra  of  particular  species  (figs.  108, 
109),  sometimes  in  great  abundance.     Witk  a  few  ammonites,  we 
also  find  mya  (fig.  Ill),  Pholadomy'a  (fig.  110},  and  Terebra'tula 
(fig.  112),  which  are  also  equally  characteristic.     Certain  beds 
of  this  formation  contain  Paludi'nse,  or  Helices,  consequently  indi- 
cating that  streams  of  fresh  water  emptied  into  the  seas  of  that 
period. 

56.  How  is  the  upper  o'olite  divided?     What   is  Kimmeridge 
What  is  found  above  the  Kimmeridge  clay  ? 

57.  What  fossils  are  characteristic  of  the  upper  o'olite  ? 


FOSSILS  OF  THE  O'OLITE. 


65 


Fig.  108.— O'strea  del 
to'idea. 


Fig.  HQ.—Pholadomy'a 
a'cutico'sta. 


Fig.  IQ9.—Ex'ogy'ra 
vir'gula. 

58.  The  lithographic  stone  of  Solenhofen,  in  Bavaria,  is  referred 
to  the  upper  strata  of  the  Jura'ssic  system ;  in  it  are  found  an  im- 
mense quantity  of  fossils,  reptiles,  particularly,  pterodactyls,  fishes, 
insects,  plants,  &c.  In  some  parts  of  upper  o'olite  are  beds  of  a 
highly  bituminous  shale  (locally  known  as  Kimmeridge  coal); 'in 
the  latest  calcareous  beds  of  the  Portland  group  are  found  cyca'dex 


Fig.  112. —  Tere.bra'tula  sella. 


Fig.  113. — Za'mia  feneo'nis. 


59.  The  o'olitic  or  Jura'ssic  system  of  rocks  is  met  with  in  Eng- 
land and  on  the  continent  of  Europe,  but  is  not  represented  in 
North  America,  where  the  transition  from  the  new  red  sandstone 
to  the  greensand  and  other  rocks  of  the  creta'ceous  period  is  abrupt. 
No  rock  answering  to  the  Lias  has  yet  been  discovered  in  the 
United  States. 

58.  To  what  geological  group  does  the  lithographic  stone  of  Solenhofen 
belong  ?     What  is  Kimmeridge  coal  ? 

59.  In  what  part  of  the  world  is  the  o'olitic  system  of  rocks  found  ?     Is 
it  known  in  the  United  States  ? 

6* 


SIXTH  GEOLOGICAL  EPOCH. 


LESSON  IV. 

SECONDARY  FORMATION  Continued. 

SIXTH  GEOLOGICAL  EPOCH. — Creta'ceous  Formation — Lower  Cre- 
ta'ceous  System — Fossils — Wealden  Deposit — Greensand — 
Gault — Fossils — Upper  Creta'ceous  System — Fossils — Extent 
of  Creta'ceous  Formation — Table  of  Formations. 

SIXTH  GEOLOGICAL  EPOCH. 

CRETA'CEOUS  FORMATION. 
(Secondary  Formation  Continued.} 

1.  Next  in  order  above  the  Jura'ssic  system  we  find,  in  discord- 
ant stratification,  immense  Creta'ceous  deposits  in  a  great  many  lo- 
calities ;  these  deposits  may  be  divided  into  several  others,  accord- 
ing to  the  discordance  of  stratification  observed  in  some  of  their 
divisions.    The  Creta'ceous  formation  (from  the  Latin,  cre/a,  chalk) 
may  be  divided  into  the  upper  and  lower  chalk. 

2.  The  LOWER,  or  INFERIOR  CRETA'CEOUS  system :   Neocomian 
of  the  French ;  the  Shanklin,  or  Lower  Green  Sand  of  the  Eng- 
lish.    The  first  deposits  formed  above  the  o'olite  are  composed  of 
marls,  then  a  yellowish  limestone,  characterized  by  great  numbers 
of  genus  Spata'ngus  (Jig.  114),  with  a  multitude  of  the  remains 
of  shells  and  polypa'na  of  different  genera.      This  limestone  is 
sometimes  in  continuous  layers  of  considerable  thickness,  some- 


Fig.  114.—- Spata'ngus      Fig.  115. — Exo'gy'ra        Fig.  116. — Lima 
retusus.  subplica'ta.  elegans. 

1.  What  is  found  next  above  the  Jurassic  formation?     Why  is  it  termed 
Creta'ceous  ?     How  is  the  creta'ceous  group  divided  ? 

2.  How  are  the  first  deposits  above  the  o'olite  characterized  ?     What  is 
lumachella  ?    What  is  found  next  above  the  yellow  limestone  ? 


CRETACEOUS  FORMATION.  67 

times  only  in  masses  agglutinated  to  each  other  by  mud  and  sand ; 
sometimes  it  is  entirely  wanting.  Above  it  are  clays  which  con- 
tain, often  in  great  quantity,  ex'ogy'ra  (Jig'  115),  and  oysters, 
among  which  is  distinguished  the  great  species,  named  Ostrea 
Leymerii  ;  the  Lima  elegans  (Jig-  116)  is  also  found.  Among 
these  clays  are  met  large  calcareous  masses,  a  good  deal  flattened, 
filled  with  the  same  fossil  sheDs,  presenting  tumachdla*  or  conchi- 
lians,  which  have  been  confounded  with  the  Portland  group,  form- 
ed by  an  accumulation  of  the  ex'ogy'ra  vi'rgula  (fig.  109).  Next 
we  have,  at  least  in  parts  of  France,  sands  and  clays,  sometimes 
variegated  in  colours,  among  which  are  masses  of  iron  ore,  com- 
monly o'olitic.  The  remains  of  shells  seem  to  give  place  here  to 
ferruginous  masses. 

3.  These  last  deposits  seem  to  be  wanting  in  other  localities,  in 
which  we  find,  instead,  great  layers  of  limestone,  more  or  less 
compact,   sometimes   white,   sometimes   coloured,  which   enclose 
hippuri'tes,spheruli'tes,and  even  nummuli'tes,  which  have  been  long 
regarded  as  belonging  to  the 

tertiary  formation.  We  also 
find  here  a  fossil  which  is 
very  characteristic  ;  it  was  at 
first  compared  to  the  diceras 
(Jig.  106),  but  is  now  call- 
ed Chama  ammonia  (fig. 
117).  This  species  of  shell, 
which  is  often  very  abundant, 
is  always  so  imbedded  in  the 
mass  of  rock,  where  it  is  dis- 
tinguished by  the  sinuosities  FiS-  H7-— Cha'ma  ammo'nia. 
it  forms,  that  it  is  very  difficult  to  detach  it  entire.  Various  spe- 
cies of  ammonites,  gigantic  hamites,  several  species  of  Crio'ceratites 
(fig.  118 — from  the  Greek,  Krios, 
a  ram,  and  Keras,  horn)  and  belem- 
nites.  The  trigo'nise,  which  are  still 
met  with  and  continued  to  the  green- 
sand,  present  here  new  species  (fig. 
119),  which  seem  to  be  characteris- 
tic. 

4.  In  the  south  of  France  and  in 

the   Pyrenees   the  chalk   formation    Fig.  us 

*  Lumachella — an  Italian  word,  formed  from  limacea,  a  snail,  which  is 
derived  from  the  Latin,  Umax.  The  word  is  used  to  designate  a  mass 
formed  of  the  remains  of  snails,  &c.  with  their  nacre,  united  by  gluten — 
It  is  also  called  conchilian  marble. 

3.  Are  sands  and  clays  everywhere  found  above  the  yellowish  limestone? 
What  fossils  are  found  in  these  limestones  of  the  creta'ccous  group? 


68 


CRETACEOUS  FORMATION. 


(View  of  Hinge.} 

Fig.  119. —  Trigo'nia  a'l&for'rnis. 

possesses  peculiar  characters,  both  in  relation  to  the  organic  re- 
mains contained  in  it,  as  well  as  its  mineralogical  relations.  We 
there  find  a  great  many  shells,  very  remarkable  for  their  form  and 
peculiar  structure,  which  are  called  hippuri'tes  (figs.  120,  121), 
^wggrT^  and  spheruli'tes  (fie;.  122).  Many 

nummuli'tes  (fig.  123),  of  which  some 
deposits  are  formed  exclusively,  are  also 
met  with.  It  is  not  determined  pre- 
cisely to  what  part  of  the  lower  chalk 
these  deposits  should  be  referred,  but 


Fig.  1 20.— Hippuri't es  lio'culata.  Fig.  1 2 1  .—Hippuri'tes  orga'nisans. 

4.  How  is  the  chalk  formation  characterized  in  the  south  of  France  ? 
"What  are  Hippurites  ? 


THE  WEALDEN  DEPOSIT. 


they  seem  to  represent  a  part  of 
the  neocomian  (or  Shanklin)  for- 
mation. In  the  Pyrenees  the  lay- 
ers are  often  of  a  deep  colour, 
and  separated  by  argilla'ceous 
schists,  which  seems  to  make 
them  a  part  of  the  transition  for- 
mation ;  but,  on  the  contrary,  in 
the  north  part  of  the  ba-sin  of 
the  Gironde,  they  belong  to  the 
chalk. 

5.  The  neocomian,  which  was 
not  at  first  distinguished  from 
other  parts  of  the  chalk  forma- 
tion, is  now  recognized  in  a 


Fig.  1%2,—Spkcruli  teg  ventricosi 
Radiuli' te.-<  lurbina'ta. 


Fig.  123. — Nummuli'tes  from  the  chalk. 

great  part  of  France,  Switzerland,  and  different  parts  of  Germany, 
Poland,  and  even  to  the  Crimea.  Here  and  there  deposits  of  gyp- 
sum of  greater  or  less  extent  are  met  with,  sometimes  isolated,  and 
sometimes  associated  with  crystalline  rocks. 

6.  The  WEALDEN  DEPOSIT. — We  frequently  meet  in  the  first 
deposits  of  the  chalk  formation  the  remains  of  organized  bodies, 
which  appear  to  belong  to  paludi'nse,  clearly  showing  there  was 
here  and  there  an  afflux  of  fresh  water  to  those  seas  in  which 
these  remains  accumulated.  We  also  find  in  the  same  situations 
deposits  of  combustibles,  which  have  always  been  known  under 
the  name  of  lignite  (from  the  Latin,  lignum,  wood),  probably  form- 
ed from  con'ifers  (as  dicoty'ledons  did  not  then  exist),  which 
were  doubtlessly  carried  by  rivers :  such  are  those  in  the  environs 
of  Orthez,  in  the  department  of  Landes  ;  of  Bellesta  and  of 
Saint-Girons,  in  the  department  of  Ariege  ;  of  Irun,  in  Guipuscoa 
(Spain),  &c.  But  all  these  local  deposits  are  nothing  compared  to 
those  which  have  long  been  described  in  England,  in  parts  of  the 
counties  of  Kent,  Surrey,  and  Sussex,  under  the  name  of  wealds, 
from  which  is  derived  the  term  wealden  formation. 

5.  What  is  the  Neocomian  deposit  ?   What  is  its  extent  ? 

6.  What  is  meant  by  Wealden  formation  ?   Why  is  it  so  called  ? 


70  THE  WEALDEN  DEPOSIT. 

7.  This  formation  is  composed  of  alternate  layers  of  limestone, 
sand,  more  or  less  ferru'ginous,  and  clay,  the  deposits  of  which  are 
sometimes  extremely  thick.     There  are  .entire  beds  of  limestone 
composed  of  paludi'nre,  constituting  what'  is  named  Purbeck  lime- 
stone.    The  lamina?  of  argilla'ceous  matter  are  often  covered  by 
cy'clades  and  anodo'ntse,  and  we  find  disseminated  a  great  number 
of  small  cypris.     TJiere  are  many  species  of  fresh  water  fishes, 
the  remains  of  fluviatile  tortoises,  mingled  with  marine  and  terres- 
trial saurians,  among  which  is  the  monstrous  i'guanodon,  which 
must  have  been  thirty  feet  in  length,  to  judge  from  the  size  of  its 

bones.  In  this  formation  are 
found  also,  in  the  dirt  of  the  Isle 
of  Portland,  the  sili'cified  stems 
of  cyca'dere  (fig.  124),  standing 
erect  in  the  midst  of  the  earth, 
of  which  the  deposit  consists  ; 
various  species  of  conifers,  equi- 
sita'ceoe,  and  ferns  are  also  met. 
The  remains  of  birds  of  the  order 
Fig.  124. — Mante'Llia  nidifo'rmis.  of  gra'lleas  (waders)also  exist,  but 

no  mammals,  although  we  have  seen  them  in  the  marls  of  the 

o'olite  (Jigs.  81,  82). 

8.  It  is  believed  that  the  clays  in  the  environs  of  Boulogne, 
which  seem  to  be  continuous  with  those  of  England  on  the  south- 
ern side  of  the  Channel,  may  be  referred  to  the  wealden  deposit, 
as  well  as  those  of  Forges  and  of  Savigny  in  the  country  of  Bray, 
where  paludine  limestones  like  those  of  Purbeck  have  been  found. 
It  is  very  certain,  according  to  the  observations  of  M.  Leymerie, 
these  deposits  are  connected  with  those  in  the  department  of  Aube, 
and  form  part   of  the  superior  neocomian  clays :  if  there  are  indi- 
cations of  fresh  water  deposits,  they  prove  the  connection  between 
the  wealden  formations  and  those  of  this  epoch. 

9.  According  to  English  geologists,  the  wealden  formation  is 
below  the  neocomian,  and  is,  consequently,  older  and  not  precisely 
contemporaneous  with  it. 

10.  Above  the  neocomian  and  wealden  formations  there  is  a 
group  of  deposits  generally  termed  Green  Sand,  consisting  of  two 
arena'ceous  beds,  with  a  parting  of  clay  called  gaidt.     The  green 
sand  formation  receives  its  name  from  the  prevalence  of  small 
green  particles  of  si'licate  of  iron  distributed  through  the  sand.     It 
is  found  in  New  Jersey.   In  England  it  is  divided  into  lower  green 
sand,  gault,  and  upper  green  sand.     This  group  consists  of  white 

7.  What  is  Purbeck  limestone  ? 

8.  What  is  the  extent  of  the  Wealden  formation  ? 

9.  Which  deposit  lies  above,  the  Neocomian  or  Wealden  ? 

10.  What  is  found  next  above  the  Wealden  and  Neocomian  ?   From  what 
does  green  sand  obtain  its  name  ?     How  is  it  divided  ? 


GREEN  SAND.— GAULT. 


71 


and  yellowish  sands,  which  are  frequently  ferruginous,  containing 
masses  of  limestone,  clays,  and  sandstones  of  more  or  less  com- 
pactness :  it  also  comprises  the  quadersandstein  and  plxmr-kalk 
of  German  geologists. 

11.  Gault  is  a  stiff  clay  of  a  blue  colour,  and  the  inferior  por- 
tion of  it  in  England  abounds  in  iron  py'rites,  while  the  upper  part 
contains  green  particles  of  the  silicate  of  iron.     Various  nodules 
and  concretions  are  found  throughout,  which  are  sometimes  fossili'- 
ferous,  but  more  frequently  obscure  and  of  doubtful  origin.    Gault 
is  a  provincial  term,  used  originally  in  the  middle  of  England  to 
designate  the  brick-clay,  which  there  belongs  to  the  creta'ceous 
system. 

12.  Above  the  green  sand  formation,  the  calcareous  part  be- 
comes more  abundant ;  at  first  it  is  mixed  with  sandstone,  and  then, 
little  by  little,  becomes  isolated,  and  now  contains  only  green  parti- 
cles of  si'licate  of  iron,  which,  from  being  at  first  very  abundant, 
gradually  disappear :  this  is  the  chloritic  chalk,  which  is  some- 
times friable,  and  at  others  solid.     The  green  particles  having 
totally  disappeared,  the  limestone  is  found  alone,  sometimes  in  form 
of  pure  chalk,  of  more  or  less  solidity,  and  occasionally  becomes 
very  compact ;  here  we  have  argilla'ceous  or  arena'ceous  limestone, 
and  finally  sands,  or  nearly  pure  sandstone.    From  these  result  the 
chalk  marlj  or  representatives  of  it. 

13.  Organic  remains 


are 


in 


very  abundant 
these  deposits,  and  in 
species  and  even  in  ge- 
nera are  very  distinct 
from  those  of  the  preced- 
ing formations.  Immedi- 
ately above  the  wealden 
is  a  marly  bed,  charac- 
terized by  the  presence 
of  a  species  of  Ex'ogy' 
ra  (Jig>  125)  five  or 
six  inches  in  diameter, 
not  known  in  the  neo- 
comian.  According  to 
M .  Leymerie,  the  nu'- 
cula  pectina'ta  (fig> 
126)  is  a  characteristic 
shell  of  the  gault  or  blue 


Fig.  125. — Ex'ogy'ra  sinua'ta. 
marl.     Belonging  to  the  green  sand 


11.  What  is  gault  ?     What  is  the  origin  of  the  name  ? 

12.  What  succeeds  the  green  sand  formation  ?    What  is  chloritic  chalk  ? 
What  is  chalk  marl  ? 

13.  What  organic  remains  are  found  in  these  deposits  ? 


72 


FOSSILS. 


formation  generally,  the  characteristic  shells  are  the  inoce'ramus 
conce'ntricus  (fig.  127),  the  plica'tula  placu'nea  (Jig-  128),  seve- 
ral species  of  ammonites,  and  particularly  the  ammonites  monile 
(Jig-  129),  which  is  quite  characteristic. 


Fig.  127.— Jnoce  ramus  con- 
ce'ntricus. 


Fig.  126. — JWcw/a  pcctina'ta  (.skell  and  mould). 


Fig.  l"Xi.—Scnplii'tes 

e'qualis. 


Fig.  128.— Plica'tula  placu'nea. 

14.  We  find  in  the  chalk  marl  the  bacilli' tes  (fig.  130),  and 
turrili'tes  (fig.  131),  different  species  of  the  first  of  which  are 
found  in  the  highest  part  of  the  chalk  formation.  To  these  may 
be  added  the  scaphi'tes  (fig-  132),  some  particular  species  of 


Fig.  129.—  Ammonites  moniU.         Fig.lZQ.—Baculi'tes. 

ammonites  (figs.  133,  134),  the  Ex'ogy'ra  columba  (fig.  135), 
the  O'strea  carina'ta  (fig.  136),  the  terebra'tula  octo'plica'ta  (Jig. 
137),  which  continue  in  "the  chalk. 

14.  What  animal  remains  are  found  in  the  chalk  marl  ? 


FOSSILS. 


73 


Fig.  134. — Ammonites  rotkomage'nsis: 


Fig.  135. — Ex'ogy'ra  columba.  Fig.  137. —  Tcrcbra'tula  octo'plica1  ta. 

Nu'cula  (from  the  Latin,  nux,  a  nut)  is  an  inequilateral  bivalve  shell;  the 
hinge  is  narrow,  and  has  many  teeth  like  those  of  a  comb :  several  species 
are  known. 

Scaphi'ics  (from  the  Greek,  scaphe,  a  boat)  is  an  eliptical,  many  cham- 
bered shell,  somewhat  resembling  the  ammonites. 

Ba'culiles  (from  the  Latin,  ba'culum,  a  stick)  is  a  multilocular,  straight, 
or  slightly  bent,  and  slightly  conical  shell ;  the  chambers  are  separated  by 
septa,  pierced  by  a  marginal  siphuncle. 

Turrili'tes  is  a  spiral,  turriculated,  multilocurlar  shell;  the  chambers  are 
separated  by  winding  septa,  which  have  the  si'phuncle  in  their  disks :  the 
aperture  is  round.  This  fossil  must  not  be  confounded  with  the  Turrite'lla, 
which  is  a  univalve,  found  both  recent  and  fossil. 

15.  The  Upper  Chalk  Formation. — In  this  we  find  chalk  with 
and  without  flints.  The  layers  of  flint  are  frequently  almost  the 
only  indications  of  stratification  afforded  by  the  mass.  It  is  fre- 
quently soft,  and  susceptible  of  solution  or  suspension,  as  in  Spa- 
nish whiting,  which  contains  an  immense  quantity  of  microscopic 
shells,  belonging  to  the  group  of  foraminifera.  In  some  cases  it 
is  arena'ceous,  and  sometimes  very  compact.  Although  often 
white,  we  find  it  in  some  places  coloured  grey,  yellow,  red,  &c. ; 

15.  How  is  the  upper  chalk  formation  characterized  ? 
7 


74 


UPPER  CHALK  FORMATIONS. 


sometimes  it  is  o'olitic  in  character,  and  becomes  almost  crystalline, 
even  magnesian,  and  in  localities  remote  from  crystalline  materials 
•which  might  affect  it.  The  inferior  part  of  this  formation  is  fre- 
quently soiled  with  clays — chalk  marl.  Above  it  is  more  pure, 
and  contains  a  great  many  nodules  of  flint  or  silex.  Though  this 
character  is  very  common,  it  is  wanting  in  a  great  many  places.  At 
its  upper  part  the  chalk  formation  becomes  very  sandy,  as  in  the 
neighbourhood  of  Maestricht. 

16.  Excepting  the  ba'culites  found  at  Maestricht,  the  remains 
of  cephalopods  are  not  found  in  the  upper  creta'ceous  formation  ; 
but  belemni'tes  (from  the  Greek,  belem'non,  a  dart)  of  particular 
species,  such  as  Jig.  138,  and  many  other  organic  remains  not 


Fig.  138. — Belemni'tes  mucrona'tus. 

met  with  in  the  chalk  marl,  are  found :  among  them  are  the  pla- 
gio'stoma  spino'sum  (fig.  139) ;  the  o'strea  vesicitla'ris  (fig.  140) ; 


Fig.  139. — Plagio'stoma  spino'sum.  Fig.  140. — O'strea  vesicula'ris. 

the  Ca'tylus  Cuvieri  (fig.  141),  the  structure  of  which  is  fibrous ; 
the  Terebra'tula  Defra'ncii  (fig.  142) ;  the  ana'nchytes  ova'tus 
(Jig.  143) ;  the  Spa'tangus  cor-ari guinum  (fig.  144). 


Fig.  141. — Ca'tylus  Cuvieri. 


Fig.  142.—  Terebra'tula 
Defra'ncii. 


16.  What  organic  remains  are  found  in  the  chalk  formation  ? 


UPPER  CHALK  FORMATIONS. 


75 


.  143. — Ana'nchytes  ova'tus. 


Fig.  144. — Spa'tangus  cor.an  guinum. 

17.  In  the  upper  part  of  these  deposits  we  find,  among  many 
other  fossils,  an  enormous  saurian,  called  the  Mosasaurus  (from  the 
name  of  the  river  Meuse,  and  the  Greek,  sauros,  lizard),  originally 
found  on  the  banks  of  the  Meuse,  in  the  celebrated  quarries  of  St. 
Peter's  Mount,  near  Maastricht  (Jig.  145).  Organic  remains  of  a 
Mosasaurus  have  been  found  in  New  Jersey. 


Fig.  145. — Head  of  the  Mosasaurus  of  Maastricht. 

"  The  Mosasaurus  is  a  genus  determined  from  a  fossil  discovered  upwards 
of  sixty  years  ago,  and  which  at  that  time  was  extremely  puzzling  to  natu- 
ralists. Its  true  place  in  the  animal  kingdom  is  now  known  to  be  among 
the  Lacertian  Saurians;  but  the  animal  appears  to  have  been  perfectly  ma- 
rine  in  its  habits.  The  head,  the  only  part  at  first  discovered,  measured 


7.  Where  is  the  Mosasaurus  found  ?     From  what  is  its  name  derived  ? 


76 


CRETACEOUS  GROUP. 


four  feet  in  length,  and  is  preserved  in  the  museum  at  Paris.  Other  paits 
have  also  been  found  from  time  to  time  in  the  Maastricht  quarries,  and  some 
fragments  in  the  chalk  of  the  south  of  England."  Ansted. 

The  whole  length  of  the  animal  was  probably  not  less  than  twenty-four 
feet,  a  magnitude  which  must  be  compared  with  that  of  the  lizards  of  the 
present  day,  and  not  with  the  crocodilians,  whose  structure  is  totally  dif- 
ferent. 

18.  We  also  find  in  the  chalk  formation  ceta'ceous  mammals, 
which  are  classed  among  the  lamantins  and  dolphins. 

19.  The  CRETA'CEOUS  GROUP  prevails  extensively  in  England 
and  on  the  continent  of  Europe.     True  white  chalk  exists  not 
only  in  England,  but  also  in  France,  in  Denmark,  in  Poland,  in 
central  Russia,  and  in  the  Caucasus.     Semicrystalline  rocks  of  the 
creta'ceous  epoch  also  exist  in  the  central  plains  of  Asia  Minor. 
Beds  of  the  creta'ceous  period  are  found  in  New  Jersey,  and  other 
parts  of  the  United  States ;  but  they  rest  on  the  oldest  secondary- 
rocks,  without  the  intervention  of  the  o'olite.     The  formation  is 
extremely  calcareous,  in  places  chiefly  arenaceous,  but  no  true 
chalk  has  yet  been  discovered  in  America ;  nor  has  o'olite  been 
found.   Fossils,  apparently  creta'ceous,  have  been  recently  obtained 
from  south-eastern  India. 

'"•  This  brings  us  up  to  the  close  of  the  secondary  formation.  As 
far  as  we  have  studied  our  subject,  we  find  the  earth's  crust  to  con- 
sist of  a  series  of  formations,  as  represented  in  the  following  dia- 
gram (fig.  146). 


Secondary . 


Chalk  with  flints. 
Chalk  without  flii 


Chalk  marl. 
Green  sands. 


Wealden. 
O'olitic  System. 


Cretaceous  Systt 


Liassic  System. 


Upper  new  red  sandstone,  orTriassic  System. 


Lower  new  red  sandstone,  or  Permian  System. 
Carboniferous  System. 


Old  red  sandstone. 


Transition. 

Metamorphic. 
Plutonic  Rocks. 


f  Devonian  System. 
Silurian  System. 


ambrian  System. 
Argillaceous  Schist. 
Mica  Schist. 


Granite. 


Fig.  146. 


18.  What  mammals  are  found  in  the  chalk  formation  ? 

19.  What  is  the  extent  of  the  creta'ceous  group  ?    Has  chalk  been  found 
in  the  creta'ceous  formation  of  the  United  States  ? 


SEVENTH  GEOLOGICAL  EPOCH.          77 

The  study  of  the  creta'ceous  rocks  brings  us,  as  it  were,  to  the 
termination  of  that  period  in  the  history  of  the  earth's  structure  to 
which  the  character  of  antiquity  belongs.  In  the  succeeding 
period,  we  shall  find  all  the  fossils  are  either  resemblances  or  types 
of  existing  organic  creatures. 


LESSON  V. 

SEVENTH  GEOLOGICAL  EPOCH.  —Tertiary  Formation  —  Eocene 
beds — Paris  Basin — Fossils — Jlnoploihe'rium — Paleothe'rium 
— Miocene  beds — Dinothe'rium — Lignites — Pliocene  beds—- 
Fossils — Bone  Caverns. 

SUPERFICIAL  DEPOSITS.  —  Drift  —  Diluvium  —  Megathe'rium — 
Boulder  Formation — Alluvium — Big  Bone  Lick. 

EIGHTH  GEOLOGICAL  EPOCH. — Modern  Formation. 

SEVENTH  GEOLOGICAL  EPOCH. 
TERTIARY  FORMATION. 

1.  Ordinarily,  geologists  designate  under  the  collective  name  of 
SECONDARY  FORMATION,  the  long  series  of  systems  of  rocks,  com- 
mencing above  the  transition  formation  with  old  red  sandstone  and 
coal  (fig.  146),  and  terminating  above  with  the  chalk  ;  and  they 
give  the  name  of  TERTIARY  FORMATION  to  those  strata  which  are 
more  recent  than  the  chalk,  and  consequently  superior  to  it,  but 
still  more  ancient  than  the  strata  of  the  present  or  modern  epoch. 

2.  During  that  period  the  seas  were  very  much  less  extensive 
than  they  were  in  the  more  remote  geological  ages,  and  conse- 
quently the  sedimentary  deposits  formed  in  those  waters  are  of  less 
extent  and  more  isolated.     Moreover,  their  formation  was  effected 
at  different  points  of  the  globe,  and  at  different  periods,  and  to  fol- 
low their  history  in  chronological  order,  it  is  necessary  to  subdivide 
them  into  three  groups.     At  the  period  contemporaneous  with  the 
deposit  of  each  one  of  these  series  of  formations,  there  existed 
particular  species  of  organized  creatures,  mingled  with  other  spe- 
cies like  the  preceding  or  succeeding  periods ;  but  the  fauna  of  all 
the  divisions  of  this  period  possesses  certain  common  characters, 
and  among  the  most  remarkable  of  these  is  the  existence  of  a 
great  number  of  mammals. 

i     1.  What  is  understood  by  secondary  formation  ?     What  is  meant  by  ter- 
tiary formation? 

2.  How  did  the  seas  of  the  tertiary  epoch  differ  from  those  of  more  re- 
mote geological  ages  ?  What  is  the  most  remarkable  characteristic  of  the 
tertiary  formation  ? 

7* 


78  TERTIARY  FORMATION. 

3.  The  Tertiary  Formation  is  divided  into  the  older,  middle,  and 
newer  tertiary  groups,  which  have  been  conveniently  designated 
by  Mr.  Lyell  under  the  names  of  Eocene,  Miocene,  and  Pliocene. 

The  first,  EOCENE  (from  the  Greek,  eos,  dawn,  and  kainos, 
recent),  designates  the  older  tertiary  strata,  in  which  there  appears, 
as  it  were,  the  first  dawn  of  existing  species. 

The  second,  MIOCENE  (from  the  Greek,  melon,  less,  and  kainos, 
recent),  is  applied  to  the  middle  tertiary  strata,  because  in  them  we 
find  more  recent  species  than  in  the  preceding  group,  but  still 
fewer  recent  than  extinct  species. 

The  third,  PLIOCENE  (from  the  Greek,  pleibn,  more,  and  kainos, 
recent),  is  given  to  the  newer  tertiary  beds,  because  there  is  always 
a  greater  number  of  recent  than  of  extinct  species  found  in  them. 

4.  The  Eocene,  or  older  tertiaries. — The  beds  thus  designated 
are  a  very  variable  series,  consisting,  in  England  and  Belgium,  of 
stiff  clays  alternating  with  sand,  and  resting  on  coarse  sand  and 
gravel ;  and,  in  Paris,  of  a  number  of  limestones  and  marls,  alter- 
nating with  gypsum  and  silicious  strata.     They  are  deposited  in 
basin-shaped  depressions  in  the  older  rocks,  and  in  England  some 
portion  of  them  has  been  so  greatly  disturbed,  that  the  beds  are 
actually  vertical. 

5.  The  older  tertiaries  of  England  are  chiefly  confined  to  three 
masses,  contained  in  trough-shaped  basins,  called  respectively,  the 

.  London,  the  Hampshire,  and  Isle  of  Wight  basins ;  a  stiff  clay 
predominates  in  them,  and,  from  being  very  abundant  near  Lon- 
don, is  known  as  the  "  London  day'''  The  London  clay  often, 
but  not  always,  rests  on  a  series  of  sandy  and  gravelly  beds,  in- 
closing bands  of  potters'  clay,  to  which  the  name  of  Plastic  clay 
has  been  given. 

6.  The  greatest  development  of  eocene  strata  in  the  United 
States  occurs  in  Virginia,  North  and  South  Carolina,  Georgia,  and 
Alabama.   In  Virginia  these  beds  consist  of  greenish  sands,  nearly 
identical  in  appearance  with  a  portion  of  the  creta'ceous  series,  and 
of  the  same  mineral  composition ;  and  a  little  further  to  the  south 
a  continuous  formation  of  white  limestone  ("Santee  limestone") 
occurs,  which  is  of  no  great  thickness,  and  which  varies  in  hard- 
ness, and  is  composed  of  comminuted  shells,  but  so  closely  resem- 
bling certain  creta'ceous  beds  of  the  secondary  period  in  New  Jer- 
sey, as  to  have  been  frequently  mistaken  for  them.     But  this 
resemblance  does  not  extend  to  the  fossil  contents  of  the  beds, 

3.  How  is  the  tertiary  period  divided?     What  is  meant  by  Eocene? 
What  by  Miocene  ?     What  by  Pliocene  ? 

4.  What  are  the  characters  of  the  Eocene  beds  ?    How  are  they  de- 
posited ? 

5.  What  are  the  chief  localities  of  Eocene  beds  in  England  ?     What  is 
London  clay  ? 

6.  In  what  parts  of  the  United  States  do  Eocene  strata  exist? 


TERTIARY  FORMATION.— PARIS  BASIN.  79 

which  are  in  many  instances  analogous,  or  the  same  as  those  of 
the  eocene  formations  in  other  parts  of  the  world. 

7.  The  geological  position  of  the  city  of  Paris  resembles  that 
of  London,  each  being  situated  upon  an  extensive  and  important 
group  of  tertiary  strata,  which  occupies  a  depression  or  basin  in 
the  underlying  chalk.     The  nature  of  the  two  deposits  is,  how- 
ever, totally  different,  the  deposit  being  characterized  in  England 
by  great  accumulations  of  argillaceous  matter,  which  form  the 
London  clay,  while  in  the  neighbourhood  of  Paris  there  is  a  varied 
series  of  limestones  and  marls,  alternating  with  important  beds  of 
gypsum  and  silicious  matter. 

8.  The  depression  in  the  chalk  forming  the  celebrated  Paris 
basin  so  frequently  named  by  geologists,  which  is  filled  up  by  these 
strata,  is  nearly  one  hundred  and  eighty  miles  in  its  greatest  length, 
and  about  half  that  in  breadth.   The  surface  of  the  chalk  is  usually 
covered  by  broken  and  rolled  flints,  often  cemented  by  a  silicious 
sand  into  a  kind  of  breccia;  and  these  flints  seem  to  mark  the 
action  of  the  sea  upon  reefs  of  chalk  before  the  commencement  of 
the  tertiary  epoch. 

The  order  of  stratification  of  the  Paris  basin  is  represented  in 
the  following  table. 

8.  Upper  marine  sands.  7.  Upper  fresh  water  sands. 

W- y, ' 

6.  Green  marls. 
5.  Gypsum. 

i    {  Calcaire  siliceux,  or  o    (  Calcaire  grossier,  or 

'  (  Fresh  water  limestone.  '  I  Marine  limestone. 

2.  Plastic  clay. 
1.  Chalk. 

9.  Above  the  chalk  we  find,  first,  deposits  of  plastic  clay,  so 
called  because  varieties  of  it  are  well  suited  for  the  manufacture 
of  pottery.     In  the  neighbourhood  of  Montereau  on  one  side,  be- 
tween Houdan  and  Dreux  on  the  other,  it  is  remarkable  for  its 
whiteness  and  purity,  and  is  used  in  the  fabrication  of  the  finest 
porcelain.     Around  Paris  it  is  coloured  and  impure,  and  suitable 
only  for  coarse  pottery.     These  clays  contain  lignite,  in  which  we 
see,  perhaps  for  the  first  time,  mingled  with  numerous  co'nifers, 
phanero'gamous  monocotyledons,  true  palms,  and  some  dicotyle- 
dons.   Marine,  as  well  as  fresh  water  shells,  are  found  in  its  upper 
part. 

7.  In  what  respects  does  the  geological  position  of  Paris  differ  from  that 
of  London. 

8.  What  is  the  extent  of  the  Paris  basin  ? 

9.  What  lies  next  above  the  chalk  in  the  Paris  basin  ?     What  are  the 
characters  of  plastic  clay  ?    To  what  uses  is  it  applied  ? 


80 


TERTIARY  FORMATION — PARIS  BASIN. 


10.  Above  the  plastic  clay 
we  find  thick  deposits  of  marine 
limestones,  more  or  less  arena- 
ceous in  structure,  the  different 
beds  of  which  may  be  easily 
distinguished  by  their  characters. 
These  limestones  contain  a  pro- 
digious quantity  of  mil'liolites 
(fig>  147)  —  extremely  small 


Fig.  147.— Mil'liolites  (greatly  mag- 

nified). 

shells — the  most  of  which  do 
not  attain  .03937  of  an  inch  in 
size,  and  yet  they  constitute  a 
great  number  of  genera.  These 
serve,  in  a  manner,  as  paste  to 
an  immense  number  of  shells 
of  different  genera,  which  are 
more  analogous  to  creatures  now 
living  than  any  we  have  hither- 
to mentioned :  three  per  cent, 
of  them  are  even  identical  with 
species  now  existing  in  the 
neighbouring  seas.  The  cerithia 
are  here  so  abundant  that  the 
formation  is  sometimes  known 
by  the  name  of  cerithia  lime- 
stone, although  these  same  fos- 
sils are  found  in  many  other  de- 
posits. There  are  certain  spe- 
cies which  are  characteristic, — 
that  is,  they  are  always  found 
wherever  these  deposits  exist  : 
such,  for  example,  is  the  Ceri'- 
thium  giga'nteum  (fig*  148), 


Fig.  148. — Ceri'thium  giga  nteum 
(very  much  reduced). 


10.  What  lies  above  the  plastic  clay  ?  What  are  mil'liolites  ?  What 
proportion  of  fossil  shells  found  in  eocene  strata  resemble  living  species  ? 
What  is  Cerithia  limestone  ? 


FOSSILS.— PARIS  BASIN. 


sometimes  twenty-seven  inches  in  length,  the  extremity  of  which 
is  almost  always  worn  or  broken  by  the  friction  and  knocks  occa- 
sioned by  the  movement  of  the  animal.  Among  other  shells,  of 
which  there  are  a  great  many  species,  it  is  difficult  to  name  any 
which  are  absolutely  characteristic ;  among  the  most  common  are 
the  Turrite'lla  imbrica- 
ta'ria  (Jig.  149);  the 
ampulla' ria  acuta  (fig- 
150) ;  the  terebe'llum 
fusifo'rme,  (fig.  151) ; 
the  milra  SCabra  (fig-  Fig.  149. —  Turrite'lla  imbricata'ria. 

152);  the  crassatella  sulca'ta  (Jig- 153);  the  car'dium  porulo'sum 


Fig.  15Q—Ampulla'ria 
acuta. 


Fig.  151. —  Terr  die' Hum 
fusifo'rme. 


Fig.  152.—Mitra 
scabra. 


(Jig.   154).     With 

these     species    are 

found  a  great  many 

others,  which  have 

been  described  and 

figured   in  a   great 

many  books  on  the  Fig.  153.—Crassate'lla  sulca'ta. 

environs  of  Paris ;   there  are  species  which  are  much  more  com- 


Fig.  154.— Car'dium  porulo'sum. 


82  PARIS  BASIN — ANOPLOTHERIUM. 

mon  than  those  named,  but  some  of  them  are  not  found  every- 
where, and  others  are  seen  first  in  the  superior  formations. 

11.  Above  the  marine  limestone,  or  rather  parallel  with  it,  we 
find  what  is  named  fresh-water  or  silicious  limestone,  so  called  be- 
cause there  is  mingled  in  it  a  considerable  quantity  of  silex,  some- 
times uniformly  disseminated,  and  at  others  forming  here  and  there 
more  or  less  voluminous  masses  (fig.  155),  which  constitute  the  mill- 

Millstone. 


Fig.  155. — Fresh-water  limestone,  with  masses  of  millstone  without  shells. 

stone  without  shells, which  is  wrought  into  millstones.  Fluviatile  shells 
are  found  in  the  lower  parts  of  this  bed,  such  as  lymnea  and  planorbis. 
12.  The  next  group  in  the  general  series  of  Paris  basin  rocks 
consists  of  white  and  green  marls,  with  a  considerable  quantity  of 
gypsum,  the  latter  being  chiefly  developed  in  the  centre  of  the 
basin.  The  upper  parts  both  of  the  marine  and  fresh-water  lime- 
stone alternate  occasionally  with  marls  ;  but  the  latter  form,  on  the 
whole,  a  distinct  overlying  group  of  fresh-water  origin,  and  contain 
land  and  fluviatile  shells,  fragments  of  wood,  and  great  numbers 
of  the  bones  of  fresh-water  fishes,  of  crocodiles,  and  other  reptiles, 
of  birds,  and  even  of  quadrupeds,  the  latter  being  usually  isolated 
and  often  entire.  The  gypsum  beds  having  been  extensively 
quarried  for  the  manufacture  of  "plaster  of  Paris"  (obtained  by 
burning  the  gypsum),  they  have  yielded  a  multitude  of  these 
mammalian  remains,  which  formed  the  base  of  the  great  dis- 
coveries of  Cuvier — so  that  the  investigation  of  them  by  that 
anatomist  may  even  be  considered  to  have  laid  the  foundation  of 
the  science  of  Paleontology,  so  far  as  it  is  dependent  on  sound 
principles  of  analogy.  It  is  chiefly  in  the  lower  parts  of  the 
gypsum  that  these  extinct  quadrupeds  are  found.  Such,  for  ex- 
ample, are  the  anoplo- 
the'rium  and  palco- 
thefriwn,  pachyder- 
matous animals,  more 


or  less  approaching  to 
the  rhinoceros  and  ta- 


pir, of  which  there 
were  several  species. 
The  common  anoplo- 
Fig.  156.— Skeleton  of  the  Anoploihe'rium  commune,  the'rium  (fig.  156 — 

11.  What  is  the  position  of  the  fresh- water  limestone  of  the  Paris  basin  ? 

12.  What  is  found  next  above  the  limestones  of  the  Paris  basins  ?    What 
is  plaster  of  Paris  ?    What  fossils  are  found  in  the  gypsum  ?    What  is  the 
Anoplothe'rium  ? 


PALEOTHERIUM.— MIOCENE. 


83 


from  the  Greek,  a,  without,  oplon,  arm,  and  therioh,  animal),  was 
of  the  size  of  an  ass,  of  a  heavy  form,  and  with  thick  short  legs 
and  a  long  tail ;  some  species  had  slender  legs,  and  must  have  been 
swift  and  active ;  and  others  of  the  size  of  a  hare,  and  even  of  a 
guinea-pig,  which  were  nevertheless  adult. 

13.  The  paleothe' rium  (fig.  157 — from  the  Greek,  palaios, 
ancient,  and  therion,  a  beast),  was  of  the  size  of  a  horse,  and  form 
of  a  tapir ;  species  of  various  size,  both  large  and  small,  existed. 


Fig.  157. — Skeleton  of  the  Paleothe'rium  magnum. 

14.  Above  the  gypsum  we  find  another  more  modern  group, 
consisting  of  two  formations,  one  marine  and  the  other  fresh- water. 
They  are  composed  of  marls,  mica'ceous  and  quartzose  sands,  and 
layers  of  flint.  These  beds  of  sand  are  often  of  great  thickness, 
and  are  at  first  coloured  by  oxide  of  iron,  and  then  white  and  pure: 
they  frequently  form  masses  of  sandstone,  sometimes  without  or- 
ganic remains,  or  only  rolled  shells  of  the  marine  limestone  ;  some- 
times, on  the  contrary,  they  contain  the  casts  or  impressions  of 
shells.  On  these  sandstones  repose  new  lacu'strine  deposits,  form- 
ing sometimes  shell  millstone,  filled  with  lymnese  (fig.  158), 
plano'rbis  (fig.  159),  and  seeds  ofchara,  or  gyro'gonites  (jig.  160). 


Fig.  158. — Lymnea 
longisca'ta. 


Fig.  159.— Plano'rbis 
cuom'phalus. 


Fig.lGQ.—Chara  medi- 
cage'nula  ? —  (greatly 
magnified.) 


15.  The  Miocene,  or  middle  tertiary  period. — During-  this 
second  part  of  the  tertiary  period  both  terrestrial  and  aquatic  ani- 


13.  What  is  the  Paleothe'rium  ? 

14.  What  lies  above  the  gypsum  ? 


84        MIOCENE,  OR  MIDDLE  TERTIARY. 

mals  became  more  numerous,  and  more  like  those  of  our  own 
times  ;  then  there  existed  a  great  number  of  mollusks,  belonging  to 
species  which  still  inhabit  the  seas  of  the  present  epoch. 

16.  In  England  the  miocene  tertiary  is  represented  by  a  thin 
and  variable  heap  of  gravelly  strata,  called  the  "  crag  formation," 
which  is  divided  into  three  parts.     The  lowest  is  called  coralline 
crag,  because  a  great  many  coral  remains  are  found  in  it ;  the 
next  is  the  red  crag,  distinguished  by  its  deep  ferru'ginous  stain  ; 
the  uppermost  is  named  Norwich,  or  mammali'ferous  crag,  which 
is  of  more  recent  origin  than  the  red  crag,  and  contains  bones  of 
large  mammals,  and  occasionally  fresh-water  shells. 

17.  An  extensive  series  of  miocene  beds  occupies  the  whole 
surface  of  both  shores  of  the  Chesapeake  Bay,  a  hundred  miles 
north  and  south,  and  fifty  miles  wide.     A  similar  series  occurs  in 
Virginia.     The  lowest  beds  of  the  Chesapeake  series  are  argilla'- 
ceous,  and  the  uppermost  are  sandy ;  both  series  abound  in  fossils, 
and  when  met  on  the  side  of  a  river  they  are  sometimes  found  to 
consist  of  little  else  than  shells  and  the  remains  of  zo'ophytes,  often 
in  a  high  state  of  preservation. 

18.  The  miocene  tertiaries  prevail  extensively  on  the  continent 
of  Europe  ia,  various  river  basins.     They  occupy  a  considerable 
portion  of  the  west  of  France,  filling  up  the  basins  of  the  Loire 
and  Garonne ;  they  fill  up  also  a  great  part  of  the  valley  of  the 
middle  Rhine,  and  the  whole  of  the  great  valley  of  Switzerland, 
between  the.  Alps  and  the  Jura  chain ;  and  from  Switzerland  they 
extend  towards  the  north-east,  following  the  course  and  partly  fill- 
ing up  the  valley  of  the  Danube.     From  point  to  point  they  may 
here  be  traced  spreading  out  into  extensive  series  near  Vienna,  and 
in  Styria,  and  occurring  again  in  the  plains  of  Hungary ;  they  are 
also  found  in  Poland  and  Russia ;  they  appear  both  in  northern 
and  southern  Italy,  and  on  the  shores  and  islands  of  the  Mediterra- 
nean. 

19.  The  miocene  beds  of  the  basin  of  the  Loire  are  chiefly  de- 
veloped near  the  city  of  Tours,  and  in  the  Touraine  district,  where 
they  consist  for  the  most  part  of  broken  shells  ;  these  beds,  how- 
ever, sometimes  afford  a  building  stone,  the  comminuted  shells 
being  mixed  with  sand  and  gravel,  and  cemented  by  calcareous 
matter.     In  Switzerland  there  is  a  series  of  tertiary  sandstones  of 
the  miocene  period ;  and  between  the  lakes  of  Geneva  and  Lu- 

15.  What  is  remarked  of  the  miocene  period,  as  respects  animals  ? 

16.  How  are  the  miocene  beds  represented  in  England  ?     What  is  coral- 
line crag  ?     What  is  red  crag  ?     What  is  Norwich  crag  ? 

1 7.  In  what  part  of  the  United  States  do  we  find  examples  of  miocene 
beds? 

18.  Where  do  we  find  miocene  beds  in  Europe  ? 

19.  What  is  the  nature  of  the  miocene  beds  in  Switzerland  ?     What  is 
molasse  ? 


MIOCENE  FOSSILS.  85 


cerne  these  beds  consist  of  a  coarse  conglomerate,  called  "  nagel- 
fluhe,"  passing  into  a  finer  sandstone  (the  "molasse"  of  French 
geologists),  which  is  usually  soft  and  incoherent,  but  sometimes 
sufficiently  hard  to  be  used  as  a  building  stone.  Various  beds  of 
lignite  and  marl  are  irregularly  distributed  through  the  molasse, 
which  are  evidently  of  fresh-water  origin. 

20.  The  marine  deposits  of  the  miocene  strata,  although  abound- 
ing in  shells,  do  not  contain  as  great  a  number  of  species  as  the 
marine  limestone  of  the  Paris  basin;  yet,  eighteen  per  cent,  of 
these  species  are  identical  with  those  now  Jiving  in  the  neighbour- 
ing seas.  There  is  often  the  strongest  analogy  between  these  new 
deposits  and  the  lower  limestones,  with  which  they  have  been 
confounded  ;  yet,  if  we  do  frequently  observe  a  common  aspect, 
and  often  find  the  same  shells  in  both,  there  is,  nevertheless,  es- 
sential differences  between  them.  In  one  case,  we  no  longer  find 
species  characteristic  of  the  lower  deposits ;  there  is  no  ceri'thium 
giga'nteum,  no  car'dium  porulo'sum,  &c. :  in  the  other,  we  find 
new  remains  which  we  did  not  meet  with  before,  such  as  the 
Bala'nus  cra'sus  (Jig.  161),  the  Rostella'riapespelica'ni  (Jig.  162), 
the  Pe'cten  pleurone'ctes  (Jig.  163),  &c.,  which  are  never  found  in 
the  Paris  basin,  but  exist  in  the  subapennine  formation. 


Fig.  161.— Bala'-     Fig.  162.— Rostella'ria  Fig.  163.— Pe'cten 

mis  crasus.  pespelica'ni.  pleurone'ctes. 

21.  The  strata  belonging  to  this  period  of  the  tertiary  formation 
contain  divers  species  of  paleothe'rium,  but  differing  from  those 
found  in  the  Paris  gypsum.  Here  we  also  find  several  other  species 
of  animals,  which  constitute  genera,  no  trace  of  which  is  met  with 
in  the  preceding  formation,  and  which  totally  disappear  in  the  suc- 
ceeding epoch.  Here  we  find  the  remains  of  mastodons  (from 
the  Greek,  mastos,  a  nipple,  and  odous,  tooth),  animals  analogous 

20.  What  is  the  character  of  the  fossils  of  these  beds  ?    What  proportion 
of  them  resemble  recent  or  living1  species? 
8 


86 


MASTODON.— DINOTHERIUM. 


to  the  elephant,  but  whose  teeth  (Jig. 
164)  have  crowns  studded  with  conical 
or  nipple-like  points,  instead  of  being 
flat.  On  the  miocene  beds  we  also 
find  the  gigantic  Dinotherium  (from 
the  Greek,  dinos,  circular,  and  therion, 
a  beast),  an  animal  resembling  the  tapir, 
which  is  remarkable  by  having  the 
tusks  turned  downwards  (fig-  165). 
It  was  first  found  in  Hesse,  afterwards 

Fig.  164. —  Tooth  of  a  ma' sto-  near  Auch  by  M.  Lartet,  who  sub- 
don  (reduced).  sequently  found  in  the  same  place  the 

bones  of  monkeys. — 

Remains  of  the  rhi- 
noceros, of  the  hippo- 

po'tamus,  and  of  the 

castor  are  also  found 

in  these  deposits. 

"The  Dinothe'rium  is 
the  largest  of  the  terres- 
trial mammalia  of  whose 
existence  we  have  any 
positive  knowledge,  but 
as  it  is  not  a  matter  of 
absolute  certainty  at  pre- 
sent of  what  nature  its  ex- 
tremities may  have  been, 
we  are  hardly  in  a  condition  to  speak  very  decidedly  of  its  general  appearance 
or  habits.  It  is  chiefly  known  by  the'  fragments  of  the  head  and  teeth, 
which  exhibit  a  near  approach,  the  former  to  the  ceta'cean  tribe,  and  the 
latter  to  the  tapir ;  but  there  is  a  remarkable  and  very  striking  anomaly  in 
the  existence  of  two  large  and  heavy  tusks  placed  at  the  extremity  of  the 
lower  jaw,  and  curved  downwards  like  the  tusks  in  the  upper  jaw  of  the 
walrus.  It  is  probable,  from  the  size  and  position  of  these  tusks,  as  well 
as  from  the  structure  of  the  bones  of  the  head,  that  the  animal  was  aquatic 
in  its  habits,  living  almost  entirely  in  the  water,  and  feeding  on  such  succu- 
lent plants  as  it  could  there  obtain. 

"  The  length  of  the  Dinothe'rium  is  calculated  to  have  been  at  least  as 
much  as  eighteen  feet,  and  its  proportions  were,  probably,  very  much  the 
same  as  those  of  the  great  American  tapir.  It  was  provided  with  a  trunk, 
which  seems  to  have  been  short,  but  extremely  large  and  powerful,  and 
capable  of  being  employed  to  tear  up  the  food  which  the  tusks,  acting'  like 
pick-axes,  may  have  loosened."  Ansted. 

22.  The  miocene  is  very  rich  in  combustible  material ;  to  it 
belong  the  lignites  of  Languedoc,  of  Provence,  Switzerland,  and 
most  of  those  of  Germany — as  well  as  the  masses  of  earthy  com- 


Fig.  1 65. — Lower  jaw  and  tusJc  of 
the  Dinothe'rium  giga'nteum. 


21.  What  fossil  animal  remains  are  found  in  these  beds  ?     What  is  the 
Dinothe'rium  ? 


LIGNITES.— MOLASSE. 


87 


bustible  in  the  neighbourhood  of  Cologne.      All  these  Hgnites 
appear  to  have  been  formed  chiefly  from  con'ifers,  the  structure  of 
which  (fig.  166)  may  be  recognised  in  the  mass  of  combustible 
itself,  or  in  the  wood  disseminated  through  various  deposits. 
C. 


Fig.  166. — Structure  of  the  wood  of  con'ifers. 
fl.  Part  of  a  transverse  section  of  natural  size. 

b.  Part  of  the  same  section  seen  under  a  microscope. 

c.  Longitudinal  section,  in  the  direction  from  B  to  C,  also  magnified. 

d.  Section  in  the  direction  from  A  to  B. 

23.  But  the  tertiary  sandstones  of  the  miocene  period  (the  mo- 
lasse)  also  contain  a  great  quantity  of  dicotyledonous  plants,  the 
wood  of  which  is  here  and  there  found  disseminated,  sometimes  in 
a  silicious  state,  and  clearly  exhibiting  the  proper  tissue  or  struc- 
ture of  this  class  of  plants  (fig.  167),  particularly  characterized 
by  the  presence  of  large  lono-i'tudinal  vessels.  We  also  find  leaves, 
C. 


a.  B.  b. 

Fig.  167. — Structure  of  the  wood  of  dicoty'ledons. 

a.  Part  of  a  transverse  section  of  natural  size. 

b.  Part  of  the  same  section,  seen  under  the  microscope,  showing  the  large 
vessels. 

c.  Longitudinal  section  in  the  direction  from  A  to  B,  showing  the  struc- 
ture of  the  medullary  rays,  and  that  of  a  large  vessel. 

22.  What  is  lignite  ?     From  what  family  of  plants  were  these  lignites 
probably  formed  ?     How  is  this  family  of  plants  recognised  ? 

23.  What  description  of  plants  exist  in  the  tertiary  sandstone  of  the 
miocene  period  ? 


FOSSILS. 


Fig.  lG8.—Leafofanun 
determined  elm. 


the  midst  of 
deposits       of 


often  in  great  numbers, 
in  the  clays  which  ac- 
company the  lignites, 
in  the  characters  of 
which  we  distinctly  re- 
cognise existing  dicoty'- 
ledons,  such  as  walnuts, 
maples,  elms,  birches, 
«fec.  (Jig*.  168,  109). 
Even  fruits  are  found 
which  re  distinguish- 
ed, often  with  difficulty, 
from  those  now  grow- 
ing. 

24.   We  also  find  in 
{h[s  formatiori5  eilher  fo 


Fig.  169.  —  Complonia  combustible  -- 
a'cutilo'ba.          ^  jn  those  Of 


Liblar  near  Cologne,  or  in  the  ar- 
gilla'ceous  or  sandy  matter  of  the 
formation,  the  remains  of  monoco- 
ty'ledonous  plants  :  there  is  wood 
presenting  the  structure  of  the 
palms,  that  is,  an  assemblage  of 
woody  fasciculi  (bundles),  longi- 
tudinally arranged,  without  regard  Fi 
to  regularity,  in  the  middle  of  eel- 


170.—  Structure  of  the  icood 


Fig.  171.  —  Palmacites  Lamanonis. 


lular  tissue,  as  seen  (fg. 
170).  Leaves  like  the 
representation  (fig.  171) 
are  also  met  with.  We 
find,  too,  in  the  miocene 
gypsum  of  the  same  na- 
ture as  that  of  the  Paris 
basin,  which  has  led  to 
the  supposition  that  they 
were  of  the  same  epoch  ; 
but  besides  this  section  of 
country  being  formed  of 
the  "molasse,"  the  or- 
ganic remains  are  not  of 
the  same  species. 

Towards  the  close  of  the 
miocene,  or  second  epoch  of 


24.  How  do  we  recognise  the  previous  existence  of  iiioiiocoty'ledonous 
plants  from  their  fossil  remains  ? 


PLIOCENE.  89 


the  tertiary  period,  a  new  upheaval  appears  to  have  taken  place  in  the 
region  of  the  Alps.  A  part  of  this  complicated  chain  of  mountains  had 
then  long  existed.  Thus  the  Alps  of  Provence  and  of  Dauphiny,  which 
belong  to  a  system  of  which  Mont-Viso  is  the  most  remarkable  point,  date 
from  the  interval  elapsed  between  the  deposit  of  the  inferior  and  upper  lay- 
ers of  the  creta'ceous  system  ;  other  portions  of  the  Alpine  region  were 
raised  up  at  the  same  time  as  the  Pyrenees,  that  is,  after  the  creta'ceous 
period ;  for  example,  the  neighbourhood  of  Castel-Gomberts,  and  in  the 
mountains  which  connect  the  Alps  to  the  Jura,  we  perceive  traces  of  an 
upheaval  contemporaneous  with  that  of  Corsica,  which  occurred  after  the 
deposit  of  the  eocene,  or  first  period  of  the  tertiary  formation ;  but  the 
greater  part  of  this  majestic  barrier  between  Italy  and  the  north  seems  to 
have  acquired  its  present  configuration,  and  to  have  attained  the  immense 
height  we  now  observe,  in  more  recent  times.  The  chain  of  the  western 
Alps  appears  to  have  been  upheaved  after  the  deposit  of  the  miocene  or 
second  series  of  the  tertiary  ;  and  the  chain  extending  from  Valais  towards 
Austria  appears  to  be  of  still  more  recent  origin. 

Dating  from  the  geological  convulsion  which  gave  to  the  western  Alps 
their  existing  prominence,  and  at  different  points  produced  the  elevation  of 
the  "  molasse,"  and  other  tertiary  strata  of  the  miocene  period,  as  well  as 
those  of  more  ancient  epochs,  Europe  presented  a  great  continental  sjfcce ; 
and  during  the  period  of  tranquillity  which  followed  this  catastrophe,  marine 
deposits  did  not  take  place  except  on  the  shores  or  in  gulfs  not  far  from  the 
centre  of  this  region,  as  in  the  subapennine  hills,  in  some  parts  of  Sicily,  and 
on  a  portion  of  the  coast  of  England  ;  but  sedimentary  deposits  occurred 
in  the  basins  or  valleys  of  still  existing  rivers,  and  in  some  lakes  of  fresh 
water  which  a  more  recent  geological  revolution  has  caused  to  disappear. 

25.  The  Pliocene,  or  newer  tertiary. — In  Europe  the  pliocene 
is  chiefly  represented  in  south  Italy,  in  the  Morea,  and  in  the  isl- 
ands of  the  eastern  archipelago ;  and  important  contemporaneous 
beds  exist  in  the  valley  of  the  lower  Rhine,  near  Bonn,  and  a  por- 
tion of  central  France,  as  well  as  in  southern  Russia. 

26.  The  pliocene  beds  are  not  all,  however,  of  the  same  age, 
and  the  beds  so  called  must  have  been  in  the  course  of  formation 
for  a  very  long  period.     Those  of  Italy  admit  of  being  subdivided 
into  two  groups,  the  older  of  which  is  called  the  sub-apennine,  and 
attains  a  great  thickness  near  Parma,  exhibiting  a  considerable 
number  and  variety  of  fossils.     These  beds  consist  for  the  most 
part  of  greyish,  brown,  or  blue  marls,  containing  calcareous  mat- 
ter, and  overlaid  by  thick  sandy  beds.     The  Sicilian  beds  are  dis- 
tinctly newer  than  these,  and  are  equally  extensive.     Marls,  with 
occasional  limestone,  form  the  great  mass  of  the  materials  of  these 
strata.     Like  the  subapennines  they  are  richly  fossili'ferous,  but 
are  chiefly  characterized  by  their  shells.     A  fresh-water  bed  of 
the  newer  period  is  found  at  (Eningen,  on  the  lake  of  Constance, 

•  and  contains  numerous  remains  of  fishes,  and  some  fragments  of 
land  animals. 

27.  From  the  eocene,  or  deposits  of  the  Paris  basin,  there  is  a 

25.  In  what  parts  of  Europe  are  the  pliocene  beds  represented  ? 

26.  Are  all  pliocene  beds  of  the  same  age?    What  is  the  character  of  the 
Sicilian  beds  ? 

8* 


90 


FOSSILS. 


progressive  increase  in  the  number  or  proportion  of  recent  species 
found :  in  the  Paris  basin  three  per  cent,  of  the  fossil  shells  are 
analogous  to  the  shells  now  .existing ;  in  the  miocene,  eighteen  per 
cent.,  and  in  the  pliocene  fifty  per  cent,  of  the  fossil  shells  resem- 
ble existing  species.  There  is  scarcely  any  analogy  between  the 
shells  of  the  Paris  basin  limestone  and  those  of  the  subapennine 
hills.  Besides  the  Balanus  crasus  (Jig.  161),  and  the  Rostella'- 
ria  pespelica'ni  (Jig.  162),  we  may  cite  the  Pleuro'toma  rota'ta 
(fig.  172),  the  Buc'cinum  prisma'ticum  (fig.  173),  the  Volu'ta 
Lambe'rti  (fig.  174),  &c.,  and  almost  all  the  shells  01  the  Mediter- 
ranean. 


Fig.  172. — Pleura' toma     Fig.  173. — Buc'cinum 
rota'ta.  prisma'ticum. 


Fig.  n4—Vplu'la 
Lambe'rti. 


Fig.  I15.—Murex 
alveola'tus. 


Fig.  176. — Astarte  Bas- 
teroli. 


Fig.  m.—Cy'prea 
coccinelloides. 


The  deposits  alluded  to  also  contain  masses  of  lignites,  which  arc  advan- 
tageously worked  in  different  localities.  Some  offer  regular  layers  of  a  sort 
of  compact  coal  (brown  coal),  accompanied  by  fresh- water  shells,  indicating 
a  tranquil  deposit  in  lakes ;  but  the  greatest  number  contain  only  irregular 
masses  of  wood,  some  of  which  present  the  texture  of  the  con'ifers.  A 
great  number  of  leaves,  analogous  to  those  of  existing  dicoty'ledons,  are 
also  found. 


27.  What  proportion  of  fossils  found  in  the  eocene,  miocene,  and  plio- 
cene respectively,  resemble  species  now  living  ? 


BONE  CAVERNS.  91 


28.  The  pliocene  beds  of  the  United  States  seem  to  belong 
chiefly  to  a  very  modern  period ;  they  exist  to  a  great  extent  in 
several  localities.     At  the  mouth  of  the  Potomac,  in  Maryland,  is 
a  series  of  clay  beds,  alternating  occasionally  with  sand.     All  the 
fossils  found  in  these  beds  are  identical  with  those  species  found 
living  on  the  neighbouring  sea-coast,  a  positive  indication  of  the 
newness  of  these  beds.     Similar  beds  exist  at  Niagara  and  in 
Kentucky,  and  in  other  parts  of  North  America ;  in  all  cases  the 
recent  deposits  are  very  striking. 

29.  While  these  lacu'strine  deposits  were  tranquilly  forming  be- 
neath the  waters,  the  then  uncovered  surface  of  the  earth  was  in- 
habited by  hyenas,  cavern  bears,  hairy  elephants,  ma'stodons,  rhi- 
noceroses, hippopo'tami  and  other  animals  belonging  to  genera  still 
in  existence,  but  the  species  of  which  are  now  lost ;  they  appear 
to  have  been  destroyed  in  the  geological  revolution  which  raised 
up  the  principal  chain  of  the  Alps,  and  gave  to  these  mountains 
their  present  configuration,  and  its  present  shape  to  the  European 
continent.     It  is  probable,  too,  that  the  same  revolution  destroyed 
the  multitude  of  animals  whose  bones  are  found  at  the  bottom  of 
certain  caverns  or  fissures  in  the  rocks,  where  they  are  buried  in  a 
sort  of  calcareous  cement,  ordinarily  of  a  reddish  colour. 

30.  BONE  CAVERNS. — The  most  ancient  caverns,  celebrated  for 
the  remains  of  mammals  which  they  contain,  are  those  of  Harz 
and  of  Franconia ;  but  since  Dr.  Buckland  has  shown  the  pro- 
priety of  removing  the  mud,  sands,  rolled  flints-,  stala'gmites,  &c., 
which  often  cover  the  bone  collections,  these  remains  have  been 
found  everywhere,  even  in  places  where  they  had  not  been  pre- 
viously supposed  to  exist. 

31.  Most  of  these  caverns  appear  to  have  had  one  or  more 
lateral  openings,  affording  easy  entrance  to  the  animals  that  fre- 
quented them,  as  places  of  refuge,  to  devour  their  prey,  and  finally 
they  came  to  them  to  die.     Here  their  bones  accumulated  through 
a  great  many  generations,  and  we  now  find  them  buried  in  a  dark 
earth,  in  or  on  which  we  recognise  their  dejections.     Often  we 
find  among  the  bones  of  a  certain  genus  of  animals  other  bones, 
having  upon  them  the  print  of  teeth,  showing  they  had  been  the 
prey  of  the  first.     The  greater  number  of  these  bones  belong  to 
the  bear  tribe,  two  species  of  which  were  larger  than  any  now 
existing ;  or  to  the  hyena  tribe,  also  larger  than  those  now  known. 
Sometimes  one,  and  sometimes  the  other  of  these  genera  predomi- 
nates ;  a  species  of  wolf  abounds  in  the  bear  caverns  of  Galenreuth 
in  Franconia :  other  carni'vora,  of  the  genus  dog,  and  those  of  the 
genus  cat,  including  species  of  cougars,  are  everywhere  in  small 

28.  In  what  parts  of  the  United  States  do  pliocene  beds  exist? 

29.  What  kind  of  animals  inhabited  the  land  while  theje-Ja&tt^gtcine  de- 
posits were  being  formed  ? 

30.  What  are  bone  caverns ?  Jf  rHE 

31.  What  are  the  features  of  bone  caverns?          '    81  Kj  I  y  p  D  Q  |TY 


92 


SUPERFICIAL  DEPOSITS. 


numbers.  The  remains  of  rodents,  of  ruminants,  also  of  large 
pachyderms  and  of  birds,  which  have  been  dragged  as  prey  to 
these  resorts,  are  also  found. 

SUPERFICIAL  DEPOSITS. 

"  The  regularly  stratified  deposits,  of  whatever  geological  period  they 
may  be,  are  in  most  parts  of  the  world  covered  up,  more  or  less,  by  a  con- 
siderable mass  of  heterogeneous  material  derived  from  the  degradation  of 
the  more  ancient  rocks.  This  mass  is  generally  unstratified,  and  deposited 
in  irregular  heaps,  partially  filling  up  valleys,  covering  low  tracts  of  level 
country,  and  sometimes  even  capping  low  hills,  but  almost  always  bearing 
marks  of  having  been  transported  from  a  distance  over  ranges  of  high 
land,  although  not  without  some  reference  to  the  present  physical  features 
of  the  country  over  which  it  has  travelled. 

"Occasionally  the  fragments  which  have  been  thus  conveyed  are  of  large 
size  and  angular,  and  in  this  case  they  are  called  "boulders,"  or  "erratic 
blocks ;"  but  such  masses  have  not  generally  travelled  to  any  very  con- 
siderable distance  from  the  parent  rock.  The  transported  fragments  are 
much  more  commonly  of  small  size,  and  rounded,  as  if  by  mutual  attrition, 
at  the  bottom  of  the  sea ;  and  in  this  state  they  have  been  often  carried  to 
very  great  distances,  and  are  found  many  hundred  miles  from  the  place 
whence  they  seem  to  have  been  derived.  They  are  then  called  '  gravel,' 
and  are  riot  unfrequently  mingled  with  bones  and  fragments  of  bones  of 
large  quadrupeds."  Ansted. 

32.  These  superficial  deposits  are  termed  DRIFT,  and  comprise 
deposits  of  water-worn,  transported  materials,  consisting  of  gravel, 
boulders,  sand,  clay,  &c. 

33.  Drift  is  divided  into  DILU'VIUM,  or  ancient  drift,  and  ALLU'- 
VIUM  (from  the  Latin,  alluo,  I  wash  upon),  or  modern  drift. 

34.    The   DILU'VIUM 

(formed  from  the  Latin, 
diluo,  I  wash  away)  co- 
vers up  the  tertiary  depo- 
sits, and  contains  fossils 
whose  origin  dates  back 
to  a  period  not  very  long 
antecedent  to  the  present. 
In  fact  the  dilu'vium,  to 
a  certain  extent,  unites 
the  tertiary  with  the  re- 
cent period.  It  contains 
the  bones  of  large  mam- 
mals, both  of  extinct  and 
recent  genera  and  spe- 
cies. Among  them  we 
may  perhaps  place  the 
enormous  megathe'rium 
Fig.  178.— Skeleton  of  the  Megatherium.  (fig-  178  —  from  the 

32.  What  is  meant  by  drift  ? 

33.  How  is  drift  divided  ?    What  is  the  difference  between  dilu'vium  and 
allu'vium  ? 


MEGATHERIUM BOULDER  FORMATION.  93 


Greek,  mcgas,  great,  and  therion,  beast),  which  was  not  less  than 
eighteen  feet  long  and  nine  feet  high.  The  skeleton  is  analogous 
to  that  of  animals  of  the  order  edentata.  The  thigh-bone  in  the 
megathe'rium  is  nearly  three  times  as  great  as  the  largest  known 
elephant ;  the  bones  of  the  instep  and  those  of  the  foot  are  of  cor- 
responding size,  the  heel-bone  projects  back  nearly  eighteen  inches, 
and  the  small  bones  of  the  foot  advanced  as  much  forwards.  The 
third  toe  is  provided  with  a  socket  to  receive  a  claw,  the  sheath  of 
which  measures  thirteen  inches  in  circumference,  and  the  core  on 
which  the  nail  was  attached  is  ten  inches  in  length.  The  fore 
limbs  were  well  adapted  for  grasping  the  trunk  or  larger  branches 
of  a  tree.  This  animal  was  slow  in  its  movements,  and  probably 
fed  on  roots,  which  its  teeth  were  admirably  adapted  for  grinding. 

35.  To  the  diluvial  drift  are  also  referred  the  great  collections 
of  bones  of  the  Icy  ocean,  on  the  coasts  of  Siberia  and  on  the 
neighbouring  islands  :  there  a  number  of  enormous  animals,  their 
flesh  preserved  through  thousands  of  years,  lie  buried  in  sands 
consolidated  by  perpetual  ice ;  in  the  same  situations  have  been 
found  stags  and  horses,  the  elephant  and  rhinoceros,  covered  with 
hair,  seemingly  indicating  that  the  species  which  then  lived  in 
northern  climates  were  enabled  to  bear,  from  being  clothed  in  fur, 
lower  temperatures  than  those  with  naked  skins  which  now  inhabit 
southern  Asia  and  Africa.     The  tusks  of  these  elephants  of  the 
ancient  world  are  sought  for  the  ivory  they  afford,  and  compete,  in 
commerce,  with  those  of  modern  elephants. 

It  is  perhaps  to  the  dilu'vium  we  must  refer  those  immense  masses  of 
rolled  debris  which  contain  gold,  platina,  and  the  diamond,  in  Brazil,  in 
Africa,  in  India,  and  in  the  Oural  mountains,  as  well  as  the  arena'ceous 
veins  of  tin  in  Cornwall  arid  Mexico. 

36.  The  BOULDER  'FORMATION,  or  ERRATIC  BLOCK  FORMATION, 
also,  is  regarded  as  a  part  of  the  diluvial  drift.     A  great  part  of 
the  plain  of  Switzerland  is  covered  at  intervals  by  fragments  of 
rock,  measuring  about  a  cubic  yard,  which  strew  the  plain,  and 
dot  the  sides  of  the  Alpine  ravines,  and  rise  on  the  opposite  side 
of  the  Jura  range,  even  to  an  elevation  of  several  thousand  feet 
above  the  sea.     The  most  concentrated  distribution  of  these  blocks 
seems  to  be  near  the  town  of  Neuchatel,  but  similar  masses  are 
also  found  on  the  summit  of  the  Mont  Saleve,  behind  Geneva. 
It  is  very  remarkable  that  a  belt  of  fragmentary  masses  (not  few 
or  small,  but  countless  and  gigantic),  differing  entirely  in  character 
from  the  formation  on  which  they  rest,  should  be  found  lying  on  a 
steep,  almost  precipitous  slope  of  nearly  bare  or  thinly -covered 
rock.     One  of  the  blocks  behind  Neuchatel,  eight  hundred  and 
fifty  feet  above  the  lake,  is  of  granite,  and  measures  between  fifty 

34.  What  is  the  position  of  diluvial  drift  ?     What  is  the  megathe'rium  ? 

35.  What  other  fossils  are  referred  to  the  diluvial  drift  ? 

36.  What  is  the  nature  of  the  Boulder  formation  ? 


94  ALLUVIUM,  OR  MODERN  DRIFT. 

and  sixty  feet  in  length,  by  twenty  feet  broad,  and  forty  feet  high, 
while  between  the  Jura  and  the  Alps  blocks  still  larger  are  in 
many  places  to  be  found — one,  out  of  a  great  number  together  in 
the  canton  of  Berne,  measuring  01,000  cubic  feet. 

37.  Erratic  blocks  and  gravel  cover  the  plain  of  central  Europe 
and  the  steppes  of  Russia.     Almost  the  whole  surface  of  North 
America,  as  far  as  it  has  been  examined,  has  been  found  covered 
with  gravel,  pebbles,  and  boulders,  varying  greatly  in  thickness, 
and  obviously  of  the  same  origin  as  similar  deposits  in  Europe ; 
and  a  region  which  has  been  called  the  great  Atlantic  plain,  ex- 
tending between  the  Alleghany  mountains  and  the  Atlantic  ocean, 
together  with  the  lower  part  of  the  great  valley  of  the  Missisippi, 
appear  to*  be  the  districts  where  it  conceals  the  underlying  deposits 
to  the  greatest  depth. 

On  the  borders  of  Lakes  Erie  and  Ontario  there  are  very  de- 
cided marks  of  the  great  drift  which  has  elsewhere  overspread 
North  America,  and  the  boulder  formation,  containing  marine 
shells,  extends  into  the  valley  of  the  St.  Lawrence,  as  far  down  as 
Quebec,  and  at  a  height  of  at  least  three  hundred  feet  above  the 
sea-level.  Below  Gluebec  there  are  large  and  far-transported  boul- 
ders in  beds,  both  above  and  below  these  marine  shells,  and 
wherever  the  contact  of  the  drift  with  hard  subjacent  rocks  is  seen, 
these  rocks  are  smoothed  and  furrowed  on  the  surface,  as  they  are 
in  similar  positions  in  northern  Europe. 

38.  ALLU'VIUM,  or  MODERN  DRIFT. — In  many  parts  of  North 
America  the  valleys  are  filled  up  to  a  depth  of  twenty  or  thirty 
feet  with  unconsolidated  beds  of  earth  of  various  kinds,  and  the 
heteroge'neous  mass   contains  in   it  abundant  remains   of   large 
pachyde'rmatous  animals,  not  now  living  in  the  country,  but  asso- 
ciated with,  and  overlaid  by  other  and  similar  beds,  in  which  occur 
the  bones  of  buffaloes,  that  have  within  a  fe\v  years  been  driven 
westward  by  the  advancing  steps  of  civilized  man.     These  beds 
all  belong  to  the  same  geological  period,  or  nearly  so,  and  a  descrip- 
tion of  one  will  be  sufficient  to  give  an  accurate  notion  of  a  multi- 
tude of  similar  bogs  and  soft  meadows  in  many  of  the  western 
states.     The  most  remarkable  is  that  known  as  the  "  Big  Bone 
Lick"  in  Kentucky. 

39.  The  Big  Bone  Lick  occupies  the  bottom  of  a  boggy  valley, 
kept  wet  by  a  number  of  salt  springs,  which  rise  over  a  surface  of 
several  acres,  and  the  substratum  of  the  country  is  a  fossili'ferous 
limestone.     At  the  Lick  the  valley  is  filled  up  to  the  depth  of  not 
less  .than  thirty  feet  with  beds  of  earth,  the  uppermost  of  which  is 
a  yellow  clay,  apparently  the  soil  brought  down  from  the  high 
grounds  by  rains  and  land  floods.     In  this  yellow  earth,  along  the 

37.  Where  is  the  Boulder  formation  met  with  ? 

38.  What  is  allu'vium  ? 

39.  What  are  the  characters  of  the  Big  Bone  Lick  of  Kentucky  ? 


EIGHTH  GEOLOGICAL  EPOCH.  95 

water-courses  at  various  depths,  the  bones  of  buffaloes  and  other 
modern  animals  are  often  found  quite  entire.  Beneath  the  clay  is 
another  layer  of  a  different  soil,  bearing  the  appearance  of  having 
been  formerly  the  bottom  of  a  marsh.  It  is  more  gravelly,  darker 
coloured,  and  softer  than  the  other,  and  in  it,  or  sometimes  in  a 
stratum  of  compact  blue  clay  alternating  with  it,  there  are  found 
innumerable  bones  of  large  mammals,  chiefly  ma'stodons,  but  in- 
cluding also  elephants,  and  extinct  species  of  animals  of  the  ox 
and  deer  tribe.  In  other  localities  the  ma'stodon  bones  are  found 
immediately  below  the  surface  in  reclaimed  marshes,  and  they  are 
sometimes  extremely  perfect,  sometimes  broken  and  water-worn. 
The  Big  Bone  Lick  would  appear  to  have  been  resorted  to,  not 
only  in  modern  times  by  the  living  races,  but  more  anciently  by 
animals  now  extinct,  for  the  salt,  and  perhaps  the  food  produced 
by  the  marsh.  The  buffalo  and  bison  are  frequently  known  to 
perish  entrapped  in  these  licks  and  swamps,  and  it  seems  evident 
that  the  ma'stodon  and  elephant  of  former  times  must,  from  their 
huge  size  and  unwieldy  forms,  have  been  at  least  equally  exposed 
to  the  same  fate.  Jlnsted,  Rogers,  fyc. 

40.  Up  to  the  present  time  all  geologists  agree  in  saying  that  in 
the  formations  of  this  period,  as  well  as  in  the  most  ancient  rocks, 
neither  human  bones  nor  any  vestige  indicative  of  the  existence  of 
man  on  the  face  of  the  earth  has  been  found,  and  it  is,  for  this  rea- 
son, probable  that  man  had  not  yet  been  created  at  the  time  of  the 
destruction  of  these  animals. 

EIGHTH  GEOLOGICAL  EPOCH. 
Modern  Formation. 

41.  New  formations  are  now  being  made,  either  by  the  effusion 
of  igneous  matter  from  the  bowels  of  the  earth,  or  by  sediment 
from  waters,  and  these  formations,  which  are  contemporaneous  with 
man,  constitute  the  modern  formation. 

42.  Since  the  last  great  catastrophe  alluded  to  (the  upheaval  of 
the  Alps),  there  has  been  a  general  repose,  which  perhaps  will  be 
disturbed  one  day  by  some  new  geological  revolution ;  by  the  up- 
heaval of  some  great  mountain  chain,  for  example,  and  by  the 
great  rush  of  waters  which  must  follow  such  a  convulsion,  new 
lands  will  rise  from  the  bosom  of  the  ocean,  and  probably  enclose 
remains  of  the  bony  frame  of  man  and  of  animals  now  existing, 
just  as  the  ancient  formations  conceal  the  solid  remains  of  creatures 
which  preceded  us  on  the  earth.     Even  now  we  have  proof  that 
things  must  pass  in  the  present  time  very  nearly  as  they  did  in 

40.  Are  human  bones  found  in  a  fossil  state,  in  the  formations  thus  far 
studied  ?     What  is  the  inference  from  the  fact  ? 

41.  What  is  meant  by  modern  formation? 

42.  Are  human  bones  any  where  found  in  a  fossil  state  ? 


96  MODERN  FORMATION. 

ages  long  gone  by-,  for  in  certain  modern  formations,  which  con- 
tinue to  be  formed  under  our  eyes,  we  find  human  skeletons  im- 
bedded in  the  substance  of  the  rock,  and  already  presenting  the 
characters  of  fossils  of  the  tertiary  period.  One  of  the  most  re- 
markable examples  of  this  kind  has  been  discovered  in  the  island 
of  Guadaloupe. 

Thus  far  we  have  presented  a  sketch  of  the  earth's  structure  as 
revealed  to  us  by  an  examination  of  its  crust,  only  in  reference, 
however,  to  the  order  of  superposition  of  its  formations,  resulting 
from  great  geological  convulsions,  and  characterized  by  the  remains 
of  animals  found  entombed  in  it.  When  we  reflect  on  the  incon- 
ceivable length  of  time  it  has  evidently  required  to  effect  all  these 
changes,  and  elevate  one  above  another  gigantic  stories  of  various 
rocks,  the  imagination  is  startled ;  when  we  see  entire  creations  of 
plants  and  animals  covering  the  surface  of  the  earth,  and  inhabit- 
ing the  waters,  disappear  after  a  time,  leaving  a  few  mutilated  re- 
mains as  the  only  trace  of  their  existence,  and  give  place  to  a  new 
flora  and  a  new  population  of  animated  creatures,  destined  to  un- 
dergo in  turn  a  similar  fate,  we  are  struck  with  astonishment,  and 
overcome  by  admiration  of  the  power  of  the  Creator  'of  things  so 
grand  and  so  beautiful. 


LESSON  VI. 

INFLUENCE  OF  INTERNAL  AGENTS  ON  THE  SURFACE  OF  THE  EARTH. 

EARTHQUAKES — Description — Effects  of — Changes  of  level  pro- 
duced by — Upheaval  and  Subsidence — Constant  level  of  seas — 
Slow  and  progressive  Subsidence — General  conclusions. 

VOLCANIC  PHENOMENA. — Explosion — Eruption — Island  of  Saint 
George — Monte-Nuovo — Jorullo —  Vesuvius — Definition  of  a 
Volcano — Submarine  Eruptions —  Volcan  of  Unalaska — Crater 
of  elevation — Formation  of  Craters — Effects  of  upheaval — 
— Form  of  Volcanic  Islands — Periods  in  the  formation  of  a 
Volcano — Interior  of  Craters — Kirauea —  Solfataras —  Volcanic 
•fishes — Lava  Currents — Characters  of  Lavas — Dykes — Gas- 
eous Volcanic  Products — Eruption  of  Mud — Solid  products 
of  Volcanoes — Trachyte  —  Obsidian — Compact  Lavas — Po- 
rous Lavas,  $c. 

1.  We  have  spoken  of  formations  and  of  their  relative  order  of 
superposition,  and  occasionally  alluded  to  the  various  causes  which 
affect  them.  From  what  we  have  said  it  might  be  inferred  that 
the  several  formations  are  so  many  concentric  spheres,  enveloping 

1.  Why  is  it  that  the  surface  of  the  globe  is  not  entirely  smooth,  free 
from  mountains  and  valleys  ? 


DESCRIPTION  OF  EARTHQUAKES.  97 

a  mass  of  fire ;  and  such  in  fact  might  have  been  the  case  had  it 
not  been  for  certain  disturbing  forces  which  have  fashioned  the 
mountains  and  valleys,  and  caused  the  dry  land  to  be  lifted  up 
above  the  waters.  Had  it  not  been  for  these  disturbing  forces, 
phenomena  analogous  to  volcanoes  and  earthquakes,  the  whole 
globe  would  have  remained  under  water,  and  man  would  not  have 
been  called  into  existence.  But  having  seen  the  general  structure 
of  the  interior  of  the  earth,  we  will  study  the  phenomena,  the  dis- 
turbing forces  which  modify  its  surface,  more  particularly  than  we 
have  yet  done. 

These  disturbing  forces  are  either  internal  or  external ;  first,  of 
the  INFLUENCE  OF  INTERNAL  AGENTS  ON  THE  SURFACE  OF  THE 
EARTH. 

It  has  been  already  stated  (page  12)  that  the  centre  of  our  earth 
is  a  mass  of  fire,  to  the  influence  of  which  many  phenomena  may 
be  referred. 

EARTHQUAKES. 

2.  Description  of  Earthquakes. — Every  one  has  heard  of  the 
terrible  scourge  which  in  a  moment  reduces  the  most  flourishing 
cities  to  a  heap  of  ruins,  and  sometimes  upturns  the  neighbouring 
country.     An  earthquake  is  often  preceded  by  rumbling,  subterra- 
neous sounds,  which  are  frequently  heard  some  time  before  the 
catastrophe.    Tremblings  more  or  less  violent  are  perceived  during 
a  few  minutes  or  seconds  only,  which  in  many  instances  are  often 
repeated  with  more  or  less  rapidity  and  force ;  in  certain  cases 
they  even  continue,  with  irregular  intervals,  during  several  days, 
or  months,  or  even  entire  years.     These  movements  of  the  earth 
are  of  different  kinds ;  sometimes  they  consist  of  jerking  horizon- 
tal oscillations,  occurring  at  irregular  intervals,  sometimes  of  verti- 
cal shocks,  that  is,  in  rapid  and  successive  rising  and  falling  of  the 
soil ;  at  other  times  of  various  twisting  movements.     Frequently 
all  the  various  motions  take  place  almost  at  the  same  moment,  and 
then  nothing  can  escape  destruction. 

3.  Sometimes  an  earthquake  is  circumscribed  in  narrow  limits  ; 
that  which  happened  on  the  2d  of  February,  1828,  in  the  island 
of  Ischia,  was  not  felt  either  in  the  neighbouring  islands  or  on  the 
continent.     Frequently,  too,  it  shakes  an  immense  surface :  for 
example,  the  earthquake  of  the  17th  June,  1826,  in  New  Grenada, 
was  felt  over  many  thousand  square  leagues.    Sometimes  it  extends 
enormous  distances,  as  in  the  case  of  the  famous  earthquake  of 
Lisbon,  which  was  felt  in  Lapland  in  one  direction,  and  Martinique 
in  another ;  and,  transversely,  from  Greenland  to  Africa,  where 

2.  What  are  earthquakes  ?     What  is  the  nature  of  the  motions  produced 
by  earthquakes  ?     What  is  the  duration  of  earthquakes  ? 

3.  What  are  the  limits  of  earthquakes  ? 

9 


EFFECTS  OF  EARTHQUAKES. 


Morocco,  Fez,  and  Mequinez  were  destroyed :  ail  Europe  expe- 
rienced its  effects  at  the  same  moment.  From  the  different  histo- 
ries of  earthquakes,  many  examples  of  this  kind  of  propagation 
might  be  adduced,  extending  more  or  less  widely.  It  may  beeren 
concluded,  from  statements  of  facts,  that  the  shock  extends  accord- 
ing to  a  great  circle,  more  or  less  inclined  to  the  equator,  and  per- 
haps over  an  entire  hemisphere. 

4.  Effects  of  Earthquakes. — Earthquakes,  when  violent,  not 
only  overturn  entire  cities,  and  the  most  solidly  built  edifices,  but 
they  cause  important  modifications"  in  the  ground  itself.  Those  of 
Calabria,  in  1783,  furnish  examples,  which  are  the  more  important 
because  the  facts  were  observed  by  the  most  distinguished  men  of 
the  times,  such  as  Vicenzio,  physician  to  the  king  of  Naples,  Gri- 
maldi,  Hamilton,  Dolomieu,  &c.,  and  also  by  a  commission  ap- 
pointed by  the  royal  academy  of  Naples.  All  was  overturned  in 
this  unhappy  country ;  the  course  of  rivers  was  interrupted  and 
changed ;  houses  were  raised  above  the  level  of  the  country,  while 
others,  frequently  at  no  great  distance,  were  sunk  down  more  or 
less ;  edifices  of  great  solidity  were  split  from  top  to  bottom  ;  cer- 
tain parts  were  raised  above  others,  and  the  foundations  pushed  up 
out  of  the  ground.  Every  where  the  surface  of  the  earth  partly 
opened,  often  in  long  crevices,  some  of  which  were  one  hundred 
and  fifty  yards  in  breadth  ;  some  of  these  were  isolated,  sometimes 
bifurcated — frequently  exhibiting  other  fissures  perpendicular  to 
their  direction  (Jig.  179);  some  were  in  form  of  rays  diverging 
from  a  centre,  like  a  broken  glass  (fig.  180).  Some  opened  at^ne 


Fig.  179.  Fig.  180. 

Crevasses  and  fissures  produced  by  earthquakes. 

moment  of  the  shock,  and  immediately  closed  again,  grinding  be- 
twixt their  parietes  the  habitations  they  swallowed  up  ;  others  in- 
variably remained  gaping  after  the  commotion,  or,  commenced  by 
a  first  shock,  were  widened  by  succeeding  shocks.  In  both  cases 
it  was  sometimes  observed  that  the  borders  of  the  split  were  on 
the  same  plane,  or  showed  a  more  or  less  projecting  swelling  up 

4.  What  are  the  effects  of  earthquakes?     What  is  the  character  of  fis- 
sures produced  by  earthquakes  ? 


UPHEAVAL  AND  SUBSIDENCE.  99 

Q\  181);  sometimes  one  of  the  parts  is  elevated  much  higher 
than  the  other  (Jigs.  182,  183),  showing  that  one  must  have  been 
raised  while  the  other  was  sunk. 


Fig.  181.  Fig.  182.  Fig.  183. 

Changes  of  level  produced  by  earthquakes. 

Again  it  happens  that  a  more  or  less  considerable  extent  of  surface  is 
suddenly  sunk,  carrying  down  plantations  and  habitations,  leaving  yawning 
chasms,  with  vertical  sides,  eighty  or  a  hundred  yards  in  depth.  In  certain 
cases  an  immense  quantity  of  water  springs  from  the  bottom  of  these  cavi- 
ties, forming  more  or  less  extensive  lakes,  sometimes  without  apparent  cur- 
rent,  and  sometimes  giving  origin  to  impetuous  torrents.  In  some  instances, 
on  the  contrary,  rivulets  were  absorbed  by  the  fissures  in  the  earth,  or  swal- 
lowed for  a  time,  or  forever. 

But,  besides  the  numerous  cracks  and  divers  chasms  which  intercept  the 
waters,  furnishing  new  springs,  and  giving  them  a  new  channel,  it  also 
happens  that  masses  of  rocks,  falling  across  valleys,  arrest  the  waters  and 
soon  form  lakes  in  the  upper  part.  Now,  these  accumulated  waters  make 
new  passages,  either  by  breaking  through  the  sides  of  the  valley,  or  by  en- 
larging some  fissure  in  the  mountain ;  or,  they  degrade,  cut  down,  the  obsta- 
cle which  retained  them,  and  soon  overturn  it  entirely  or  in  part  Hence 
arise  those  fearful  outbreaks,  those  impetuous  torrents  rolling  down  enor- 
mous masses  of  rock,  the  ravages  of  which  are  as  disastrous  as  the  earth- 
quake itself,  and  which,  excavating  new  channels,  or  widening  and  deep- 
ening those  that  waters  before  pursued,  mark  their  course  by  the  debris 
which  they  roll  down  and  successively  deposit. 

When  the  principal  effects  of  earthquakes  took  place  on  the  continent 
between  Oppido  and  Soriano,  the  phenomena  extended  as  far  as  Messina, 
across  the  straits ;  more  than  half  the  city  was  destroyed,  and  twenty-nine 
hamlets  or  villages  were  swallowed  up.  The  bottom  of  the  sea  was  sunk, 
and  disturbed  at  various  points ;  the  shore  was  rent,  and  the  whole  ground 
along  the  port  of  Messina  was  inclined  towards  the  sea,  suddenly  sinking 
several  yards ;  the  whole  promontory  which  formed  its  entrance  was  swal- 
lowed in  a  moment. 

5.  Upheaval  and  Subsidence. — The  earthquakes  which  occurred 
on  the  coast  of  Chile  in  1822,  1835,  and  1837,  have  produced 
effects  not  less  remarkable.  Different  parts  of  the  coast,  from 
Valdivia  to  Valparaiso,  that  is,  an  extent  of  more  than  two  hundred 
leagues,  were  evidently  elevated  above  the  waters,  as  well  as  many 
neighbouring  islands  as  far  as  those  of  Juan  Fernandez ;  the  bot- 
tom of  the  sea  to  a  considerable  extent  participated  in  this  phe- 
nomena. On  the  coast,  rocks  which  had  been  previously  under 
water  were  raised  two  or  three  yards  above  its  level,  with  the  mol- 

5.  Give  some  examples  of  upheaval  and  subsidence  produced  by  earth- 
quakes. 


100  UPHEAVAL  AND  SUBSIDENCE. 

lusks  which  lived  on  their  surface ;  rivers  emptying  on  the  coast 
became  fordable  where  they  had  been  navigable  by  small  vessels ; 
well-known  anchorages  were  diminished  in  depth  to  a  correspond- 
ing extent,  and  at  different  points,  shoals  now  oppose  the  passage 
of  vessels  of  large  draught  where  they  readily  floated  before. 

Analogous  circumstances  occurred  in  India  in  1819;  a  hill,  fifty  miles 
long  and  sixteen  broad,  was  raised  up  in  the  midst  of  a  flat  country,  barring 
the  course  of  the  Indus.  Further  to  the  south,  on  the  contrary,  but  parallel 
to  the  same  direction,  the  country  sank,  carrying  down  the  village  and  fort 
of  Sindre,  which  nevertheless  remains  standing,  half  submerged.  The 
eastern  mouth  of  the  river  became  more  shallow  in  many  places,  and  por- 
tions of  its  bed  which  had  been  fordable  suddenly  ceased  to  be  so. 

The  history  of  all  times  and  of  all  places  furnishes  us  with  facts  of  exactly 
the  same  nature.  Everywhere  we  are  told  of  fissures  in  the  earth,  of  pro- 
found chasms,  in  which  cities  and  even  entire  countries  are  swallowed,  from 
which  flow  mephitic  gases,  enormous  masses  of  water,  sometimes  cold, 
sometimes  hot,  sometimes  even  flaming.  Also  of  plains  suddenly  trans- 
formed  into  mountains,  of  shoals  raised  in  the  midst  of  the  ocean,  of  moun- 
tains rent  and  overturned,  of  mountainous  regions,  of  hundreds  of  leagues 
of  rocks  all  at  once  levelled  and  replaced  by  lakes.  Of  water-courses 
changed,  swallowed  in  chasms  of  the  earth ;  of  lakes  which  dry  up  by 
breaking  through  their  bounds,  or  suddenly  lost  in  subterraneous  conduits, 
instantaneously  formed.  In  opposition,  we  also  learn  of  enormous  springs 
producing  new  streams,  suddenly  rising  through  a  fissure  of  a  rock,  without 
any  knowledge  whence  the  waters  come :  of  thermal  springs  which  have 
become  instantaneously  cold ;  of  others,  on  the  contrary,  appearing  where 
they  did  not  exist  before.  All  these  phenomena  are  so  many  indications  of 
fissures  in  the  earth,  which  afford  new  channels  to  waters  which  might 
have  circulated  there  before. 

6.  Relatively  to  the  sea-coasts,  these  phenomena  are  often  men- 
tioned by  authors  in  a  peculiar  manner ;  rarely  do  we  see  it  expli- 
citly announced,  there  is  an  elevation ;  but  the  event  is  stated  in 
other  terms,  referring  the  effect  to  the  most  moveable  element.  In 
this  way  authors  speak  of  the  sea  having  retired  more  or  less,  leav- 
ing its  bed  dry,  either  permanently  or  only  for  an  instant :  some- 
times, on  the  contrary,  they  mention  that  the  sea  suddenly  over- 
flowed more  or  less  elevated  coasts.  Geologists  translate  these 
indications  by  the  term  oscillation^  if  the  phenomenon  be  mo- 
mentary, and  by  the  terms  upheaval,  or  subsidence  of  coasts,  if  it 
be  permanent,  because  they  refer  these  effects  to  the  solid  parts  of 
the  globe,  and  not  to  the  sea,  the  level  of  which  does  not  vary. 
Nevertheless  it  must  be  borne  in  mind  that,  if  these  transitory  phe- 
nomena may  sometimes  be  attributed  to  oscillations  of  the  earth, 
they  may  also  arise  from  a  real  impulse  communicated  to  the 
waters  of  the  sea,  and  possibly  partake  of  both  causes.  We 
know,  in  fact,  that  during  earthquakes  the  sea  is  sometimes  vio- 
lently agitated,  that  its  waters,  elevated  to  considerable  heights, 
occasionally  make  fearful  irruptions  on  the  land,  advancing  and 

6.  What  is  meant  by  oscillation  ?  What  is  meant  by  upheaval  ?  What 
by  subsidence  ? 


CONSTANT  LEVEL  OF  SEAS.          101 

retiring  again,  carrying  devastation  over  a  greater  or  less  extent. 
These  impetuous  movements  of  advance  and  retreat,  accompanied 
by  sudden  dislocations  caused  by  subterraneous  commotions  in  the 
solid  crust  of  the  globe,  may  occasion  frightful  havoc.  The  his- 
tory of  the  Grecian  archipelago,  of  the  islands  of  Japan,  and  of  a 
multitude  of  places,  is  full  of  disasters  produced  by  these  catas- 
trophes. 

The  various  effects  produced  by  earthquakes  under  our  eyes,  and  those 
cited  in  the  most  authentic  narrations,  tend  to  confirm  what  is  transmitted 
to  us  from  the  most  remote  times,  although  we  might  state  the  facts  in  other 
terms.  Who  dares  formally  to  contradict  Pliny,  relating,  according  to  the 
historians,  that  Sicily  was  separated  from  Italy  by  an  earthquake ;  that  the 
island  Cy'prus  was  separated  from  Syria  by  the  same  means ;  and  that  of 
Eubre'a  (Negropont)  from  Bosotia,  &c.  ?  We  would  not  even  positively  deny 
the  existence  of  the  Atlantis,  swallowed  by  the  waters,  according  to  Egyp- 
tian tradition,  in  a  dav  and  a  night.  Let  us  rather  declare,  that  the  assem- 
blage of  observations  we  have,  evidently  shows  that  immense  upheavals  and 
subsidences  have  for  a  long  time  formed  part  of  the  mechanism  of  nature,  in 
bringing  the  surface  of  the  earth  to  the  configuration  we -now  observe. 

7.  Constant  level  of  seas. — We  have  just  admitted  the  subsid- 
ence and  upheaval  of  coasts,  and  laid  down  the  principle  that  the 
level  of  seas  is  invariable  :  but  this  last  assertion  being  contrary  to 
opinions  commonly  received  by  the  world,  it  is  necessary  to  sup- 
port it  by  demonstration.  The  laws  of  hydrostatics  teach  us  that 
a  mass  of  liquid  cannot  be  permanently  elevated  or  depressed  at 
one  point  of  its  surface,  but  that  a  level  must  be  established  after 
oscillation,  great  or  small,  ceases.  Hence  it  follows  that  the  level 
of  the  sea  cannot  be  stationary  at  one  point,  without  its  being  so 
throughout,  and  that  the  waters  cannot  be  elevated  or  depressed  in 
one  spot,  without  similar  changes  being  experienced  at  all  points 
of  the  same  basin.  Now  we  know  thousands  of  localities  where 
the  surface  of  the  sea  has  not  undergone  the  least  variation  since 
the  most  remote  historic  times ;  therefore  the  level  has  not  changed, 
and  its  constancy  is  the  most  positive  fact  we  are  aware  of,  be- 
cause it  has  been  subject  to  the  proof  of  all  ages.  On  the  other 
hand,  if  we  could  be  led  to  suppose,  like  the  inhabitants  of  Chile, 
seeing  the  manifest  change  on  their  coast,  that  the  sea  has  sub- 
sided there,  we  must  also  conclude,  with  the  inhabitants  of  Cali- 
fornia, Peru,  Brazil,  &c.,  that  in  those  places  it  underwent  no 
variation.  It  must  also  be  admitted  that  the  sea  has  risen  at  the 
bottom  of  the  Gulf  of  Arabia,  as  it  has  done,  in  different  epochs,  on 
the  coasts  of  Portugal,  in  the  Straits  of  Messina,  &c.  All  these 
circumstances  are  incompatible  with  each  other,  and  opposed  to 
the  laws  of  hydrostatics ;  and  hence  we  conclude,  that  instead  of 
the  immutability  of  the  ground,  which  an  error,  analogous  to  the 
idea  of  immobility  of  the  globe,  has  created,  we  must  admit  immu- 

7.  Does  the  sea  always  maintain  the  same  level  ?     What  reasons  lead  to 
the  opinion  that  the  level  of  seas  is  always  the  same? 
9* 


102  SLOW  AND  PROGRESSIVE  SUBSIDENCE. 

lability  of  the  seas,  by  acknowledging  that  the  solid  surface  of  our 
planet  is  susceptible  of  elevations,  depressions,  and  all  kinds  of 
disturbances. 

The  slow  upheaval  of  Sweden  has  already  been  noticed  (p.  20). 

8.  Slow  and  progressive  subsidence. — There  is  no  doubt  that, 
for  four  centuries  past,  the  western  coast  of  Greenland  is  continu- 
ally sinking,  through  an  extent  of  two  hundred  leagues  north  and 
south ;  ancient  buildings,  both  on  the  low  islands  and  on  the  con- 
tinent, have  been  gradually  submerged  ;  and  it  has  been  frequently 
necessary  to  move  various  establishments  built  near  the  shore, 
farther  inland.     Subsidence  of  certain  islands  in  the  South  Seas  has 
been  indicated  ;  but  in  those  places,  so  rarely  visited  by  geologists, 
the  facts  are  not  yet  clearly  established. 

9.  General  conclusion. — It  must  now  appear  to  be  well  estab- 
lished, that  earthquakes  are  capable  of  producing  great  modifica- 
tions of  the  earth's  surface,  since,  within  our  times,  vast  tracts  of 
country  have  been  elevated  sensibly  above  the  level  of  the  sea.  It 
is  not  less  evident  there  is  a  slow  power  in  operation,  in  virtue  of 
which,  different  parts  of  our  continents  may  also  be  successively 
raised ;  and  that  it  also  produces  gradual  sinkings  as  well  as  sud- 
den subsidences,  which  are  doubtless  correlative  phenomena. 

All  these  circumstances,  however  remarkable,  are,  nevertheless, 
not  very  astonishing,  when  we  reflect  on  the  enormous  dispropor- 
tion which  exists  between  the  thickness  of  the  solid  crust  of  the 
globe,  and  the  mass  of  melted  matter  it  envelopes.  Is  it  surprising 
that  such  a  crust,  a  mere  rind,  relatively  almost  as  thin  as  a  coating 
of  gold-leaf  on  an  orange,  should  be  disturbed  in  every  manner  by 
the  least  movement  of  the  subjacent  mass,  particularly  if  we  bear 
in  mind  that  similar  movements  doubtlessly  have  been  taking 
place  ever  since  the  first  pellicle  was  consolidated  on  the  surface, 
and  all  the  successive  crusts  must  have  been  rent  in  every  direc- 
tion, and  therefore  their  mass  could  not  afford  the  resistance  of  a 
continuous  envelope  ? 

VOLCANIC  PHENOMENA. 

10.  General  notion — Explosion — Eruption. — Volcanic  pheno- 
mena are   closely  connected  with   earthquakes;   they  are,  in  a 
manner,  the  final  results  of  them.     When,  by  the  shaking  and  ele- 
vation of  the  ground,  the  terrestrial  crust  is  deeply  broken,  a  tem- 
porary or  permanent  communication  is  established  between  the 
interior  and  exterior  of  the  globe,  through  which  various  kinds  of 
matter  are  disengaged  from  the  bosom  of  the  earth.     Through  the 
crevices  escape  gases  of  different  kinds,  waters  hot  or  cold,  simple 

8.  Is  there  any  evidence  of  the  slow  and  gradual  subsidence  of  land  ? 

9.  Why  is  it  believed  that  earthquakes  modify  the  earth's  surface  ? 

10.  What  are  volcanic  phenomena?     Give  some  instances  of  volcanic 
phenomena. 


VOLCANIC  PHENOMENA.  103 

or  sulphurous,  and  loaded  with  mud,  are  the  most  simple  transi- 
tory results.  But  frequently  there  are,  also,  through  the  upheaved 
and  broken  ground,  amidst  violent  detonations,  explosions  which 
eject,  to  a  great  distance,  all  the  debris  of  the  formation,  as 
happened  at  Saint-Michel,  in  the  Azores,  in  1522,  where  the 
debris  of  two  hills  covered  the  whole  city  of  Villa-Franca.  It 
most  frequently  happens,  at  the  same  time,  that  more  or  less  con- 
siderable eruptions  of  incandescent  matters  take  place,  consisting 
of  scoria?,  pumice,  &c.,  in  a  melted  state,  which  are  either  projected 
to  a  distance,  or  run  on  the  slopes,  or  accumulate  on  the  spot  to  a 
greater  or  less  height ;  this  has  occurred  in  a  great  many  localities. 

Eruption  of  the  island  of  Saint  George. — In  tho  month  of  May  1808,  in 
the  island  of  Saint  George,  one  of  the  Azores,  the  soil  in  the  midst  of  culti- 
vated fields  after  being  upheaved  opened  at  many  points  with  a  fearful  noise. 
It  first  formed  a  vast  cavity,  or  crater,  of  100,000  square  yards,  then  a 
smaller  one  at  the  distance  of  a  league,  and  finally  twelve  or  fifteen  little 
craters  on  the  broken  surface.  An  enormous  quantity  of  scoriae  and  pumice 
was  projected  to  a  distance,  and  the  ground  was  covered  a  yard  and  a  half 
deep  over  an  extent  a  league  wide  and  four  leagues  long.  For  more  than 
three  weeks  afterwards  currents  of  melted  matter  flowed  from  the  principal 
crater  to  the  sea. 

Monte-Nuovo. — Monte-Nuovo,  formed  in  1538,  at  the  bottom  of  the  bay 
of  Baia,  on  the  coast  of  Naples,  is  another  example  of  a  similar  eruption. 
Violent  earthquakes  had  continued  during  two  years  :  on  the  27th  and  28th 
September  they  did  not  cease  either  day  or  night ;  the  plain  found  between 
Lake  Averne,  Montc-Barbaro  and  the  sea,  was  then  upheaved,  and  various 
cracks  were  evident,  Sfc.  (Pietro  Giacomo  di  Toledo).  Then  a  great  extent 
of  ground  was  elevated,  and  suddenly  assumed  the  form  of  a  growing  moun- 
tain ;  in  the  night  of  the  same  day  this  little  mountain  of  earth  opened  with 
a  great  noise,  and  vomited  flames,  as  well  as  pumice,  stones  and  cinders 
(Porzio).  The  pumice  came  froifr  the  upheaval  of  the  soil,  which  consists 
of  this  material  throughout  Campa'riia ;  and  the  stones  and  cinders  came 
from  the  eruption  which  occurred  at  the  moment :  we  still  see  on  the  south 
side  of  the  mountain  a  ridge  of  scoriae,  and  on  its  summit  the  crater  which 
produced  them.  The  eruption  lasted  seven  days,  and  the  matters  projected 
and  ejected  partly  filled  Lake  Lucrin.  From  that  time  the  most  perfect 
tranquillity  has  prevailed. 

Jorullo. — There  was  something  analogous,  but  under  peculiar  circum- 
stances, in  what  happened  in  Mechoacan,  n<?ar  the  town  of  Ario,  on  the 
29th  September,  1759,  after  an  earthquake  of  two  months  duration.  In  the 
midst  of  a  plain  covered  with  sugar-cane  and  indigo,  and  traversed  by  two 
rivulets,  there  formed  in  a  single  night,  says  M.  Humboldt,  a  gibbosity 
(bunching  up)  160  yards  high  near  the  centre,  covered  by  thousands  of 
small  smoking  cones,  in  the  midst  of  which  were  raised  up  six  great  hil- 
locks, arranged  in  one  line  (Jig.  1 84),  in  the  direction  of  the  volcanoes  of 
Colima  and  of  Popocatapetl.  The  highest  of  these  hillocks,  called  Jorullo, 
was  more  than  five  hundred  yards  in  height  above  the  plain  ;  from  its  sides 
escaped  a  great  quantity  of  lavas. 

Vesuvius. — Something  similar  must  have  occurred  in  Vesuvius,  for  Strabo 
describes  the  mountain  so  called  by  the  ancients  without  in  any  way  allud- 
ing to  the  remarkable  cone  which  now  exists  (fig.  185),  and  which  he 
would  not  have  failed  to  mention.  It  is  evident  this  cone  did  not  then 
exist ;  but  the  crests  which  rise  in  semicircles  on  the  north,  forming  what 
is  new  called  the  sotnma,  probably  constituted  part  of  a  complete  circle ;  the 


104 


VOLCANIC  PHENOMENA. 


Fig,  184. —  Volcan  of  Jorullo* 

south  half,  which  was  much  more  arched,  and  separated  from  the  other  by 
a  diametrical  split,  only  offers  now  a  trace  at  the  east,  and  an  indication  at 
the  west  by  the  pumice  tufa  of  Salvatore.  The  mountain,  which  is  proba- 
bly represented  in  fig.  186,  teas,  says  Strabo,  very  fertile  on  its  slopes;  its 


Fig.  185.  —  View  of  Vesuvius 
as  it  now  is. 


Fig.  186. — Vesuvius  in  the  lime 
of  Strabo. 


summit  was  truncated,  in  a  great  part  ignited,  entirely  sterile,  of  a  burnt 
aspect,  exhibiting  cavities  filled  with  cracks  and  calcined  stones ;  from  which 
it  may  be  conjectured  that  these  places  were  formerly  burning  craters.  All 
leads  to  the  belief  that  the  cone,  which  alone  bears  the  name  of  Vesuvius 
now,  all  the  products  of  which  differ  from  the  rocks  of  the  sojnma,  was  not 
formed  till  long  afterwards,  and  probably  at  the  time  of  the  famous  eruption 
in  the  year  79,  which  cost  the  life  of  the  Roman  naturalist ;  it  then,  with- 
out  doubt,  formed  a  permanent  conduit  in  the  midst  of  the  matters  which 
are  raised  in  form  of  a  dome,  and  which  has  been  enveloped  by  subsequent 
gcoriee.  This  catastrophe  seems  to  have  produced  but  little  lava,  but  a  hor- 
rible upheaval,  which  precipitated  a  great  part  of  the  mountain  into  the  sea 
(Pliny  the  younger),  and  buried  Herculaneum  and  Pompeii,  not  under  tor- 
rents of  melted  matter,  as  commonly  said,  but  under  avalanches  of  pumice 
which  previously  existed  on  the  slope  of  the  mountain,  for  Vesuvius  itself 
has  never  produced  an  atom.  If  the  whole  south  slope  turned  towards  the 
sea  is  now  occupied  by  lava,  it  is  evident  that  before  the  formation  of  the 
permanent  volcan  it  was  covered  with  pumice  tufa,  traces  of  which  are  still 
Been  at  different  points,  the  same  as  now  on  the  external  slope  of  the  somma, 
and  in  all  Campa'nia. 

11.  Definition  of  a  Volcan. — In  those  events,  it  often  happens 
that  the  rent,  which  has  given  rise  to  observed  effects,  fs  obstructed 
or  closed  at  a  considerable  depth,  and  tranquillity  is  entirely  re- 
stored, as  'at  Monte-nuevo.  Under  other  circumstances,  on  the 

11.  What  is  a  volcan,  or  volcano  ? 


SUBMARINE  ERUPTIONS.  105 

contrary,  the  rent  forms  a  permanent  conduit  at  once,  or  after  seve- 
ral shocks  in  the  same  place.  In  this  case  there  is  sometimes 
established  a  continuously  active  furnace,  from  which  gaseous 
matter  in  abundance  is  disengaged,  or  from  which  lava  continu- 
ously boils,  and  from  which  there  is  an  incessant  projection  of 
scoriae ;  this  has  been  the  case  at  Stromboli  from  the  remotest 
antiquity.  At  other  times  the  conduit  is  temporarily  obstructed  at 
its  upper  part ;  but  the  least  effort  is  sufficient  to  remove  the  ob- 
struction, or  to  produce  a  new  opening  in 
the  vicinity,  through  some  fissure  which 
communicates  with  the  principal  conduit 
(Jjg>  187).  In  all  cases,  the  result  is  a 
centre  of  easy  communication  between 
the  interior  and  exterior  of  the  earth,  and 
it  is  this  which  is  called  a  volcan  or  vol-  _£  Q/S^^^fe 

cano.  Fig.\81. —  Volcanic  conduits. 

This  facility  of  communication  is  probably  a  preservative  against  the  vi'o- 
lence  of  earthquakes ;  indeed  it  has  been  observed  that,  from  the  moment  an 
eruption  takes  place  anywhere,  the  shocks  which  had  been  felt  up  to  that 
time,  become  fewer  and  weaker,  and  even  cease  altogether.  The  earthquake 
of  Caraccas,  in  1812,  terminated  by  the  eruption  of  the  volean  of  Saint- 
Vincent,  in  the  Antilles ;  the  eruption  of  Jorvllo,  and  that  -of  Montc-Nuevo, 
terminated  the  earthquakes  which  desolated  the  surrounding  countries.  On 
the  contrary,  when  a  volcano  becomes  inactive,  it  seems  to  announce  earth- 
quakes ;  in  1797,  when  the  volcan  of  Purace,  near  Popayan,  had  ceased  to 
emit  flame  and  smoke,  the  valley  of  Quito  was  agitated  by  violent  shocks. 
Volcans,  therefore,  seem  to  be  natural  vents,  designed  by  Providence  to  pre- 
vent a  complete  destruction  of  the  globe,  and  its  inevitable  rupture  into  frag- 
ments, which,  launched  into  space,  might  there  describe  new  orbits. 

12.  Submarine  eruptions. — It  is  not  only  on  land  that  volcanic 
phenomena  occur ;  they  also  take  place  under  the  sea,  as  might 
be  naturally  anticipated.  In  our  own  times,  we  have  had  formed  in 
this  manner  the  island  of  Julia,  in  1831,  on  the  south-west  of  Sicily  ; 
Bogoslaw,  in  1814,  in  the  Aleutian  Archipelago ;  Sabrina,  and 
another  one  not  named,  in  1811,  in  the  Azores,  where,  previously, 
at  different  epochs,  others  were  formed,  according  to  the  most 
authentic  histories.  The  same  thing  occurred,  at  different  times, 
around  Iceland :  and  various  accounts  indicate  that  in  the  islands 
of  Sunda,  the  Philippines  and  Moluccas,  throughout  the  Pacific,  in 
the  Kuriles,  Kamtschatka,  &c.,  similar  phenomena  took  place. 

Volcan  of  Unalaska. — One  of  the  most  striking  examples  is  furnished  by 
the  island,  which  arose  in  1796,  about  ten  leagues  from  the  northern  point 
of  Unalaska,  one  of  the  Aleutian  islands.  At  first  a  column  of  smoke  rose 
above  the  surface  of  the  sea ;  then  a  black  point  appeared,  the  smmit  of 
which  launched  forth  sheets  of  fire  and  stones  with  violence.  This  pheno- 
menon continued  for  several  months,  during  which  the  island  grew  succes- 
sively in  extent  and  height;  later,  srnoke  only  issued,  which  ceased  altoge. 
ther  four  years  afterwards.  Still  the  island  continued  to  enlarge,  and  to  rise 

12.  Do  volcanic  eruptions  take  place  on  land  exclusively  ? 


106  PHENOMENA  OF  SUBMARINE  ERUPTIONS. 

without  any  apparent  ejection ;  and,  in  1806,  it  formed  a  cone  which  might 
be  seen  from  Unalaska,  and  upon  it  were  four  other  smaller  ones,  on  the 
north-west  side. 

Santorin. — The  Mediterranean  also  furnishes  a  fine  example  of  submarine 
eruptions,  in  the  midst  of  the  space  comprised  between  the  islands  of  San- 
torin, Teresia  and  Aspronisi  (Jig.  193),  which,  according  to  the  ancients, 
appeared  above  the  water  several  centuries  before  the  Christian  era,  in  con- 
sequence of  violent  earthquakes.  In  this  circuit,  Hiera  arose  first,  186  years 
before  our  era,  which  subsequently  grew  by  little  islets  rising  on  its  borders 
in  the  years  19,  726,  1427  ;  then,  in  the  same  way,  Micra-Kamcni,  in  1573, 
and  Nea-Kameni,  in  1707,  were  formed  ;  and  successively  growing  in  1709, 
1711,  1712,  &,c.  No  crater  was  formed  in  either  of  these  islands,  and  we 
only  have  there  the  appearance  of  volcanic  matter  in  form  of  a  dome,  which 
seems  to  have  covered  the  orifice  through  which  it  escaped.-  There  was  no 
volcan  there,  according  to  the  terms  of  our  definition,  but  a  tendency  to  form 
one  at  some  future  time.  The  islands  of  Milo,  Argentiera,  Polino,  Polican- 
dro,  Poros,  &c.,  are  formed  of  the  same  materials,  and  probably  had  the  same 
origin. 

13.  Wlmt  passes  in  these  phenomena. — These  submarine  phe- 
nomena are  announced  by  incandescent  matters  ejected  above 
water ;  by  scoria?  and  pumice,  which  float  on  the  surface  ;  by  burn- 
ing rocks,  which  appear  in  the  midst  of  waves  of  vapour,  and  by 
the  boiling  of  the  sea,  the  temperature  of  which  becomes  very 
niuch  increased.  All  these  things  occurred  in  our  own  times,  at 
Julia,  at  Sabrina,  &c.,  and  are  such  as  authors  mention  in  detail,  in 
all  their  accounts.  Father  Goree  has  given  us  a  history  of  the 
upheaval  of  Nea-Kameni,  of  Santorin,  in  1707 ;  and  all  the  cir- 
cumstances he  relates  agree  with  what  Strabo,  Pliny,  Plutarch  and 
Justin  tell  us  of  the  appearance  of  Hiera,  in  the  midst  of  flames, 
and  a  violent  ebullition  of  the  sea. 

But  the  circumstances  we  have  just  spoken  of  are  not  always  all  present 
at  the  same  time.  Sometimes  no  solid  rock  appears  above  water;  this 
was  the  case  at  Kamtschatka,  in  1737,  where  jets  of  vapour,  great  ebul- 
lition of  the  sea,  and  pumice-stones  floating  on  the  surface,  were  all  that 
was  perceived ;  but  when  the  spot  could  be  approached,  there  was  found  a 
chaiu  of  submarine  mountains,  where  there  had  been  previously  a  depth  of 
more  than  a  hundred  fathoms.  In  certain  cases  there  is  not  even  a  jet  of 
vapour,  and  the  phenomenon  is  manifested  by  the  heat  of  the  water  only ; 
this  happened  in  1820,  at  the  island  of  Banda,  among  the  Moluccas,  where 
the  bay,  which  was  upwards  of  fifty  fathoms  deep,  was  filled  by  the  tranquil 
elevation  of  compact  basa'ltic  matter,  probably  pre-existing,  which  formed 
an  elevated  promontory  composed  of  large  blocks  piled  one  on  the  other ; 
and  its  appearance  was  manifested  by  the  heat  of  the  water  only.  It  also 
seems,  that  after  eruptions,  there  is  often  a  peaceful  and  slow  upheaval,  as 
in  the  island  formed  before  Unalaska,  and  at  Santorin,  according  to  the 
observations  of  M.  Virlet.  Indeed,  between  Micra-Kameni  and  the  port  of 
Phira,  where  there  is  an  abrupt  submarine  mountain,  there  was,  at  the  be- 
ginning of  the  present  century,  fifteen  fathoms  of  water  above  the  highest 
part ;  but  there  were  only  four  fathoms  in  1830,  and  little  more  than  two  in 
1834.  It  is  presumed  a  new  island,  that  is,  the  summit  of  a  new  cone, 
will  appear  in  the  gulf,  and  the  appearance  will,  probably,  be  accompanied 
by  such  phenomena  as  we  mention. 

13.  What  phenomena  occur  in  submarine  eruptions  ? 


VOLCANIC  PHENOMENA.— CRATERS.       107 

Let  us  add  that  islands  which  rise  to  the  surface  of  seas  do  not  always 
remain.  Many  of  them  disappear  after  a  longer  or  shorter  period,  either 
by  being  washed  down  by  the  waves,  as  is  supposed  to  have  been  the  case 
with  the  island  of  Julia,  or  by  their  mass  sinking  into  an  abyss  formed  be- 
neath them  ;  the  last  circumstance  doubtlessly  happened  to  an  island  which 
was  elevated  in  1719,  near  Saint-Michael  (Azores),  and  disappeared  in 
1723,  leaving  in  its  place  a  depth  of  seventy  fathoms.  In  the  same  region 
there  was  an  island  in  1 633,  where  there  is  now  a  bottomless  abyss. 

14.  Crater  of  upheaval,  or  elevation. — The  first  effect  of  an 
eruption  is  to  burst,  by  its  violence,  the  crust  of  the  earth  in  the 
direction  which  matters  pent  up  in  the  interior  have  taken  to 
escape.     The  ground,  no  matter  of  what  nature,  is  at  first  raised 
to  a  more  or  less  considerable  extent,  or  arched  like  a  bell,  and 
often  cracked  in  every  direction  ;  at  once,  the  explosion  occurring, 
as  if  by  the  action  of  a  formidable  powder-blast,  an  opening  is 
made  in  the  form  of  a  funnel,  through  which  often  escape  gaseous 
and  other  matters  which  caused  the  event.    It  is  to  these  initiatory 
openings,  which  may  be  made  anywhere,  to  which  the  name  of 
crater  of  elevation  has  been  given,  from  the  necessity  of  distin- 
guishing them  from  all  that  may  subsequently  occur  in  the  series 
of  volcanic  phenomena.     The  hillock  itself  which  is  produced  on 
the  soil,  by  the  first  effect,  is  called  the  cone  of  elevation,  to  distin- 
guish it  from  analogous  hillocks  which  are  often  formed  also  by 
the  accumulation  of  incoherent  materials  ejected  from  the  volcano. 

15.  Character  of  these  openings. — What  characterizes  craters 
of  elevation,  and  enables  us  to  recognise  them  in  places  where 
there  is  no  account  of  an  eruption,  is,  the  disposition  or  arrange- 
ment of  the  upheaved  strata,  being  very  different  from  what  is 
everywhere  else  observed.    These  beds  are  here  found  inclined  all 

round  the  axis  of  the  cone,  as  in  the 
section  (fig.  188),  rising  more  and 
more  from  the  base  to  the  summit, 
and  presenting  their  abrupt  escarp- 

ment"  T1* the  interior  of  the 

cavity.  Monte-Nuovo  is  an  exam- 
ple in  miniature :  the  mountain  was  formed  by  elevation,  hollowed  at 
its  summit  by  ejecting  gases  and  incandescent  matters ;  and  the 
cavity,  which  can  be  examined  now,  has  around  it,  at  an  inclination 
of  thirty  degrees,  strata  of  different  formations,  which  in  all  the 
rest  of  Campa'nia  are  horizontal.  The  semicircle  of  the  somma 
presents  the  same  characters  in  the  inclined  tables  of  amphige'nic 
porphyries,  and  analogous  circumstances  exist  in  many  other 
localities. 

16.  Another  character,  not  less  important,  and  especially  useful 
when  the  upheaved  matters  are  not  divided  into  beds,  is  furnished 

14.  What  is  a  crater  of  elevation  ?    What  is  a  cone  of  elevation  ? 

15.  How  are  craters  of  elevation  characterized  ? 


108 


VOLCANIC  PHENOMENA.— CRATERS. 


us  in  great  craters  of  elevation  by  the  crevices  or  cracks  which 
extend  from  the  margin  of  the  escarpment  to  the  external  base  of 
the  mountain,  forming  what  are  named  barancos  in  the  Canary 
islands,  where  they  are  so  remarkable.  One  of  these  barancos 
(or  ravines)  much  deeper  than  the  others,  extends  from  the  foot  of 
the  mountain  to  the  bottom  of  the  crater,  as  is  shown  in  the  follow- 
ing view  (Jig.  189).  This  last  character  is  seen  almost  always  in 


Fig.  189.  —  View  of  the  Island  of  Palma. 

the  different  localities  produced  by  similar  events,  as  well  as  in 
most  islands  which  have  been  upheaved  in  our  times  in  the  midst 
of  the  ocean ;  frequently  there  are  many  valleys  of  the  same  kind. 

Remarks  on  the  formation  of  craters. — We  have  mentioned  explosion  as 
determining,  definitely,  the  formation  of  the  crate'riform  cavity  at  the  sum- 
mit of  the  upheaved  mass  ;  however,  it  is  not  probable  that  this  circum- 
stance, which  is  applicable  to  Monte-Nuovo,  the  island  of  St.  George,  &c., 
is  constantly  seen  in  all  cases;  it  seems  to  be  even  totally  inadmissible  in 
certain  craters  of  vast  extent  known  to  exist  in  a  number  of  places.  But 
this  explosion  is  not  even  necessary.  In  fact  it  is  easy  to  conceive  that 

after  a  fracture,  as  in  fig.  190, 
which  is  a  correlative  result  of  ele- 
vation, it  may  happen  that  all  the 
erect,  eolumri-like  masses,  and  all 
the  elongated  points  between  the 
rents,  might  be  tumbled  down  at  the 
same  moment,  or  by  a  subsequent 
action.  Hence  results  an  open  cavi- 
ty (fig.  191),  the  margin  of  which 
is  formed  by  all  the  debris,  and  the 
depth  is  in  proportion  to  the  sum  of 
the  voids  or  spaces  formed  by  the 
fractures.  On  the  other  hand,  it  is 
clear  that  elevation  is  produced  by 
some  matter,  liquid  or  gaseous, 
which  pushes  the  crust  of  the  earth 


and  forces  it  to  swell  upwards  ;  now, 
if  it  happen  that  this  matter  should 
find  exit  at  some  other  point,  or  re- 
tire again  into  the  bowels  of  the 
earth,  the  upheaved  part  being  left 
without  support  may  sink  into  the 
abyss  left  beneath  it,  and  conse- 
quently cause  an  immense  vacuity 
in  the  midst  of  the  gibbosity  or 
Fig.  191.  hillock,  then  merely  forming  a  mass 


16.  How  are  craters  of  elevation  distinguished  when  the  upheaved  mat- 
ters are  not  divided  into  beds  ? 


VOLCANIC  PHENOMENA.—  CRATERS. 


109 


hollow  in  the  centre,  and  cracked  on  the  margin.  This  must  have  taken 
place  in  many  cases,  and  notably  in  the  mass  of  Etna,  (fig.  192),  the  east- 
ern slope  of  which  presents  a  vast  excavation,  called  Val  del  Bove,  which  is 
bounded  by  high  ridges,  cracked  at  various  points. 


Lava  of  1822.    - 


Terminal  cone. 
ValdeBove. 


LavaoflGGO.    • 


C.VTANEA. 


Islands  of  Cyclops. 


Fig.  192. — Plan  of  Etna  and  its  environs,  according  to  the  relievo  of 
M.  Elie  de  Beaumont. 

This  comment  need  not  be  regarded  as  a  simple  theoretic  speculation ; 
there  are  many  examples  of  similar  excavations,  independent  of  the  effects 
produced  by  earthquakes.  At  the  summit  of  Mount  Etna  there  is  one  of 
1300  feet  in  depth,  which  dates  from  1832,  and  many  others  which  were 
produced  at  the  end  of  the  last  or  beginning  of  the  present  century.  Fre- 
quently lakes  are  formed  on  a  sudden,  sometimes  of  boiling  water,  by  the 
sinking  of  the  land  consequent  on  volcanic  eruptions,  as  in  1835,  near  the 
ancient  Cesarea  in  Cappadocia ;  in  1820,  in  St.  Michael's  (Azores),  &c.  It 
has  also  happened  that  high  volcanic  mountains  have  at  once  sunk,  their 
place  being  at  once  filled  by  deep  lakes,  as  the  volcano  of  Papadayann  in 
Java,  in  1772,  which  carried  away  with  it  forty  villages  built  on  its  sides : 
as  also,  in  1638,  the  peak  of  the  Moluccas,  which  could  be  perceived  twelve 
leagues  at  sea.  We  know  that  the  summit  of  Carguarai'zo  which  rivalled 
Chimborazo  in  height,  crumbled  in  1698,  and  the  same  occurred  to  Capac- 
TJrcu,  also  situated  on  the  plane  of  Quito,  a  short  time  before  the  arrival  of 
the  Spaniards  in  America.  Many  other  facts  of  a  similar  kind  could  be 
adduced  in  support  of  the  theory  advanced. 

17.  Effects  subsequent  to  elevation. — The  crate'riform  cavities 
we  have  spoken  of  sometimes  remain  tKe  same  as  when  first  pro- 
duced ;  often,  however,  various  volcanic  phenomena  subsequently 
occur  at  different  times  and  in  various  ways.  In  this  manner  it 
was  that  the  cone  of  Vesuvius  (Jig.  185)  was  formed  in  79  in  the 
ancient  crater  of  the  Somina  (p.  104) ;  that  the  peak  of  Teneriffe 
is  found  in  a  circle,  the  vertical  walls  of  which  rise  from  600  to 
1200  feet;  that  the  volcan  of  Taal,  in  Luzon,  one  of  the  Philip- 
pine islarids,  is  in  the  centre  of  a  basin  filled  with  water,  and  sur- 

17.  Do  craters  of  elevation  always  remain  the  same  as  when  first  pro- 
duced  ?   Give  some  examples  of  the  secondary  effects  of  eruptions. 
10 


110 


VOLCANIC  ISLANDS. 


rounded  by  elevated  rocks,  having   a   single  opening  only  for 
entrance  &c. 

Islands  which  have  been  elevated  in  the  midst  of  the  sea  frequently 
exhibit  phenomena  of  the  same  kind.  Thus  the  islands  of  Santorin,  The- 
resia,  Aspronisi,  (Jig.  193),  which  were  elevated  long  before  the  Christian 
era,  present  the  appearance  of  a  vast  crater  of  elevation  :  their  slopes  are 
gentle  (Jig.  193)  externally,  but  abrupt,  on  the  contrary,  towards  the  centre 


Theresia. 


Santorin. 


Fig.  193. — Section  of  Santorin  and  adjacent  islands. 

of  the  circle  of  which  they  form  the  margin.  The  ground  is  composed  of 
various  strata,  inclined  outwardly,  among  which  are  limestone  and  argilla'- 
ceous  schist.  In  the  middle  of  the  circle,  the  depth  of  which  is  considera- 
ble on  the  borders,  all  the  subsequent  volcanic  phenomena  were  produced, 
and  here  the  three  summits  of  cones  successively  appeared,  which  consti- 
tute three  modern  islands,  and  are  still  preparing  new  eruptions. 

Something  similar  is  seen  in  the  Gulf  of  Bengal,  on  the  Island  of  Barren, 
discovered  in  1787.  It  is  a  vast  circle  (Jig.  194)  formed  of  high  moun- 
tains, into  which  the  sea  penetrates  by  a  single  opening,  and  has  a  volcan 
in  the  centre  which  was  in  full  activity  at  the  time  of  the  discovery. 


Fig.  194.—  View  of  the  Island  of  Barren  in  the  Gulf  of  Bengal 

18.  'Similarity  of  configuration  in  Volcanic  Islands. — Different 
volcanic  islands  which  have  been  formed  under  our  eyes,  as  it  were, 
in  the  midst  of  the  ocean,  are  entirely  analogous  to  those  we  have 
mentioned.  The  island  of  Sabrina,  at  the  moment  of  its  appear- 
ance, presented  a  crater  which  opened  to  the  south,  (jigs.  195, 196), 
and  terminated  by  an  opening,  through  which  issued  a  current  of 
boiling  water:  according  to  the  accounts,  the  island  of  Julia  must 
have  been  somewhat  analogous  ;  and  the  history  given  by  Captain 
Thayer,  reported  by  Poeppig,  shows  such  to  have  been  the  case. 
On  the  6th  September,  1835,  to  the  north  of  New  Zealand,  this 
navigator  almost  witnessed  a  submarine  eruption,  which  presented 

18.  How  do  volcanic  islands  differ  from  each  other  in  form  ? 


VOLCANIC  ISLANDS. 


Ill 


Fig.  195.  Fig.  196. 

Appearance  and  form  of  certain  volcanic  islands. 

an  annular  rock,  almost  on  a  level  with  the  surface  of  the  sea,  in 
the  midst  of  which  was  a  lagune  having  a  single  outlet,  and  in 
which  the  water  was  burning.  Now,  these  islands  appear  to  be 
nothing  more  than  points  of  domes  upheaved,  like  those  in  the 
gulf  of  Santorin,  either  instantaneously  or  slowly,  and  having  the 
summit  broken,  like  Monte-Nuovo.  These  are  true  craters  of 
elevation  or  of  explosion,  as  we  would  call  them ;  and  as  such 
they  may  consist  of  solid  rocks,  or  of  various  tufas,  or  even  of 
scoriae  accumulated  on  their  borders.  The  archipelago  of  the 
Azores,  which  have  so  often  witnessed  rising  from  the  sea  similar 
islands,  which  time  has  destroyed,  presents  us  one  which  seems  to 
have  escaped  destruction,  to  exhibit  to  us  how  all  those  were 
formed  which  have  disappeared.  This  is  the  rock  of  Porto  de 
Ilhco,  which  presents  a  vast  circle,  into  which  vessels  enter  for 
shelter;  its  sides  rise  400  feet  and  are  composed  of  volcanic  tufa. 

19.  These  phenomena  explain  to  us  the  origin  of  a  great  many 
islands  found  in  the  ocean  (Jig-  197),  both  by  the  analogy  of  their 
form  to  those  we  have  named,  and  their  nature.     Some  are  in  the 
form  of  a  horse-shoe,  having  a  more  -,  ^^ 

or  less  expanded  opening,  which   //-— — O"S        0 
gives  access  to  the  middle  of  the 
deep  basin  they  enclose,  and  in  the 
centre  of  which  isolated  volcanic 
hillocks    are    occasionally    found.   Fig.  197. — Disposition  of  certain 
Others  are  entirely  circular,  having         islands  in  the  South  Seas 
some  of  the  points  of  the  circle  more  or  less  broken,  or  groups  of 
small  islands  arranged  in  a  circle,  which  are  more  or  less  promi- 
nent above  the  water. 

20.  Different  periods  of  the  formation  of  a  volcan. — We  may 
often  distinguish  in  the  mass  of  a  volcanic  mountain,  several  dif- 


o 


19.  How  do  volcanic  phenomena  explain  the  origin  of  certain  islands  ? 


112  VOLCANIC  PHENOMENA. 

ferent  parts,  each  of  which  corresponds  to  a  particular  mode  of 
formation.  The  first  gibbosity  or  hill  is,  in  general,  the  effect  of 
elevation  of  the  pre-existing  soil,  which  may  be  of  any  kind  or 
nature.  Afterwards,  sooner  or  later  a  fissure  is  formed,  which 
produces  either  a  crater  of  elevation  or  a  dome  of  pasty  matter, 
as  at  Jorullo,  clearly  detached  from  the  first  hillock;  and,  as  a  last 
result,  in  the  midst  of  one  or  the  other  a  permanent  chimney  is 
formed.  Often  the  formation  of  the  terminal  cone  then  commences, 
by  the  scoriaceous  matters  raised  by  the  melted  lava  filling  the 
primitive  conduit,  which  overflows  the  margin  of  the  aperture,  or 
it  is  ejected  into  the  air,  from  which  it  falls  again  around  the  centre 
of  eruption,  accumulating  in  cones  with  a  maximum  slope  of  from 
30°  to  35°.  These  loose  scoriae  melt  on  the  side  towards  the  inte- 
rior of  the  chimney,  which  they  narrow  more  and  more  by  the  suc- 
cessive cornice-like  projections  they  form,  and  in  this  way  conceal 
the  true  diameter  of  the  crater. 

21.  It  is  rare  that  these  three  kinds  of  formations  are  all  found 
in  the  same  volcano ;  but  we  always  find  the  gibbosity  produced  by 
elevation,  and  one  or  the  other  of  the  secondary  domes.  At  Tene- 
riffe  there  is  a  broken  dome  Avhich  was  upheaved  in  the  middle  of 
a  crater  of  elevation.  At  Vesuvius,  from  the  constant  solidity  of 
the  base,  and  other  circumstances,  we  may  infer  the  existence  of  a 
central  nucleus,  produced  in  the  same  way  as  a  dome,  in  the  year 
79,  afterwards  enveloped  in  loose  materials,  and  bearing  on  its 
summit  a  true  cone  of  scoriae.  At  Etna  (fig.  198)  we  clearly 


Fig.  198. —  View  and  profile  of  Etna,  and  the  surrounding  country,  r- 

distinguish  the  primitive  hill  or  gibbosity,  showing  sheets  or 
coats  of  ancient  upheaved  lavas,  on  the  middle  of  the  slightly- 
arched  surface,  which  all  this  part  of  the  island  presents ;  it  is 
terminated  by  an  almost  level  surface,  the  Piano  del  Lago,  in 
the  midst  of  which  rises  the  terminal  cone  of  scoriae,  regularly  cir- 
cumscribed on  all  sides,  and  clearly  separated  from  the  base  on 
which  it  was  formed.  On  the  slopes  are  small  cones  of  eruption, 
formed  here  and  there,  at  different  times,  which  have  since  contri- 
buted to  the  swelling  up  of  the  whole  of  the  surrounding  land. 

22.  It  is  clear,  that  the  cones  of  scoriae  constructed  in  the  man- 
ner just  mentioned,  at  the  bottom  of  volcanic  gulfs,  cannot  be  very 
solid  ;  they  often  change  their  form  at  every  eruption.  Sometimes 
the  edifice  rises  more  and  more ;  sometimes,  on  the  contrary,  it 

20.  Are  volcans  always  characterized  by  the  .same  kind  of  formations  ? 

21.  Do  we  always  find  in  one  volcano  all  the  kinds  of  formation  ?     What 
one  is  always  found  ? 

22.  What  are  the  characters  of  cones  of  scorice  found  at  the  bottom  of 
volcanic  gulfs  ? 


INTERIOR  OF  CRATERS. 


crumbles  into  more  or  less  considerable  shreds,  and  hence  cones 
are  deeply  broken  in  all  manners  of  shape.  Sometimes  the  whole 
mass  is  swallowed  at  once  in  the  abyss  it  covered,  and  is  recon- 
structed by  subsequent  eruptions.  This  took  place  in  the  terminal 
cone  of  Etna,  which  has  several  times  disappeared  entirely  Cleaving 
an  immense  aperture,  without  parapet,  in  the  midst  of  a  little  plain 
which  crowned  the  original  gibbosity  or  hill.  At  Vesuvius  only 
the  upper  part  of  the  cone  has  ever  been  modified. 

23.  Interior  of  craters.  —  Contrary  to  the  expectation  of  all  those 
who  visit  volcanoes,  the  interior  of  craters  seldom  possesses  much 
that  is  worthy  of  observation.     After  great  eruptions,  during  which 
they  cannot  be  approached,  these  cavities  (which  are  of  conical 
form,  and  have  a  more  or  less  extensive  diameter  at  the  top,  with  a 
bottom  apparently  formed  of  a  sheet  of  consolidated  lava,  which 
covers  the  principal  chimney)  ordinarily  present  for  observation 
merely  jets  of  sulphurous  vapours,  escaping  here  and  there  from 
fissures  in  the  soil,  from  interstices  in  blocks  of  crumbled  scoriae,  or 
a  greater  or  less  number  of  small  cones  raised  up  in  different 
places.     Occasionally  we  see  one  or  more  gulfs,  sometimes  filled 
with  vapours  which  escape  continually,  and  sometimes  revealing 
the  incandescent  lava  in  the  depth  ;  sometimes  silent  and  dark, 
inspiring  with  terror,  but  without  possessing  the  least  interest  for 
observation.     In  long  intervals  of  crises,  traces  of  volcanic  action 
often  entirely  disappear  ;  in  certain  instances  even  the  sides  of 
the  crater  become  covered  by  vegetation,  as  is  related  of  Vesuvius 
before  the  eruption  of  1631. 

24.  There  are,  however,  some  observations  worthy  attention. 
The  crater  of  Stromboli,  which  has  been  in  continuous  activity  from 
the  most  ancient  times,  still  presents  phenomena  identical  with 
those  recorded  by  Spallanzani,  in  1788.     It  is  constantly  full  of 
melted  lava,  which  alternately  rises  and  sinks  in  the  cavity.  Having 
reached  to  twenty-five  or  thirty  feet  of  the  edge,  this  lava  swells, 
is  covered  with  large  vesicles  or  blisters,  which  speedily  burst  with 
a  noise,  permitting  the  escape  of  an  enormous  quantity  of  gas,  and 
projecting  scoriaceous  matters  on  all  sides.     It  immediately  sinks, 
after  an  explosion,  then  rises  again,  to  produce  the  same  effects, 
which  are  in  this  way  repeated  at  regular  intervals  of  some  mi- 
nutes. 

25.  If  the  lava  of  Stromboli  were  less  fluid,  it  is  conceived,  that 
having  reached  to  its  highest  point,  it  would  there  stop,  assume  an 
arched  form,  and  become  consolidated  into  a  more  or  less  elevated 
cone  ;  and  then,  if  an  explosion  occurred  at  a  certain  instant,  a  new 
conical  crater  would  be  found  in  the  middle  of  the  old  one.     This 

23.  What  is  found  in  the  interior  of  craters  ? 

24.  What  is  remarked  of  the  crater  of  Stromboli  ? 

25.  What  would  probably  be  observed,  if  the  lava  of  Stromboli  were  less 
fluid  than  it  is  ? 

10* 


114 


INTERIOR  OF  CRATERS. 


explains  what  frequently  takes  place  in  volcanoes,  and,  for  exam- 
ple, at  Vesuvius  (fig.  199),  where  domes  have  been  raised  which 
remained  for  a  long  time,  and  were  subsequently  broken,  giving 
passage  to  lavas,  and  finally  sank  into  abysses  left  beneath  them. 
Certain,  craters,  having  a  widely  extended  bottom,  often  contain 
hills  of  considerable  height,  which  have  had  an  origin  such  as  we 
have  described ;  either  the  lava  is  arrested  at  a  certain  height,  in 


Fig.  199. — Adventitious  Crater  >  in  the  middle  of  Vesuvius,  in  1829. 

form  of  a  cap,  or  swelled  up  at  different  points,  or  elevations  took 
place  in  different  matters  which  had  filled  the  cavity. 

26.  Sometimes,  in  place  of  lava,  there  is  found  at  the  bottom  of 
craters  boiling  sulphur,  as  was  seen  at  Vulcano,  and,  on  a  larger 
scale,  at  the  volcan  of  Taal,  in  the  island  of  Luzon,  and  at  that  of 
Azufral,  to  the  north  of  Quito,  in  the  Andes ;  hills,  and  even 
domes  of  sulphur,  are  also  mentioned,  as  M.  Boussingault  observed 
at  the  volcan  of  Pasto. 

A  crater  now  often  mentioned  by  voyagers  is  that  of  Kirauea,  on  the  island 
of  Hawaii,  one  of  the  Sandwich  group.  This  vast  cavity  is  three  and  a 
half  miles  long  and  two  and  a  half  wide,  and  over  a  thousand  feet  deep : 
Captain  Wilkes,  in  his  narrative  of  the  United  States  Exploring  Expedition, 
states  that  "  the  city  of  New  York  might  be  placed  within  it,  and  when  at 
its  bottom  would  be  hardly  noticed.  A  black  ledge  surrounds  it  at  the  depth 
of  660  feet,  and  thence  to  the  bottom  is  384  feet.  The  bottom  looks  in  the 

26.  Is  anything  found  at  the  bottom  of  craters  besides  lava  ? 


VOLCANIC  PHENOMENA.— SOLFATARAS.  115 

daytime  like  a  heap  of  smouldering  ruins.  The  descent  to  the  ledge  appears 
to  the  sight  a  short  and  easy  task,  but  it  takes  an  hour  to  accomplish. 

"All  the  usual  ideas  of  volcanic  craters  are  dissipated  upon  seeing  this. 
Tiierc  is  no  elevated  cone,  no  igneous  matter  or  rocks  ejected  beyond  the 
rim.  The  banks  appear  as  if  built  of  massive  blocks,  which  are  in  places 
clothed  with  ferns,  nourished  by  the  issuing  vapours. 

"What  is  wonderful  in  the  day,  becomes  ten  times  more  so  at  night. 
The  immense  pool  of  cherry-red  liquid  lava,  in  a  state  of  violent  ebullition, 
illuminates  the  whole  expanse,  and  flows  in  all  directions  like  water,  while 
an  illuminated  cloud  hangs  over  it  like  a  vast  canopy." 

27.  Solfata'ras. — There  are  a  great  many  craters  which  for  a 
long  time  have  not  given  exit  to  any  lava,  and  are  reduced  to  dis- 
engaging, in  greater  or  less  abundance,  sulphurous   gas,  which 
escapes  by  a  multitude  of  fissures  in  the  soil,  and  often  accompa- 
nied by  aqueous  vapour.     Hence  the  name  of  Solfata'ra  has  been 
given  to  those  places  where  these  phenomena  are  more  or  less 
developed.     Thefe  are  some  craters  which  seem  to  have  been 
always  in  this  state.     Such,  for  example,  is  the  Solfata'ra  of  Pouz- 
zouli,  in  the  kingdom  of  Naples,  which  is  a  vast  crater  of  eleva- 
tion, at  the  bottom  of  which  are  found  broken  volcanic  rocks,  daily 
decomposed  by  the  vapours.     This  solfata'ra  is  of  the  highest  anti- 
quity, and  appears  never  to  have  presented  other  phenomena  than 
those  now  observed.     When  in  repose,  volcanic  craters  become 
more  or  less  active  solfata'ras. 

28.  It  is  not  uncommon  to  find  one  or  more  lakes,  frequently  of 
great  depth,  at  the  bottom  of  craters  and  solfata'ras.     The  waters 
they  contain  are  sometimes  quite  pure,  but  they  are  often  .charged 
with  various  salts,  or  sulphurous  or  sulphuric  acid,  as  was  seen 
in  the  volcan  of  Teschem,  in  the  island  of  Java,  prior  to  1817, 
the  year  when  this  mountain  was  entirely  destroyed  by  the  action 
of  gas. 

29.  Commencement  of  eruptions. — Continuous  emissions  of  gas 
or  scoriaceous  matter  from  certain  volcans,  must  not  be  confounded 
with  eruptions,  which  are  sudden  events,  fortunately  transitory, 
often  bringing  desolation  over  an  entire  country.     When  an  erup- 
tion is  about  to  take  place  it  is  ordinarily  preceded  by  earthquakes, 
after  which  it  suddenly  occurs  with  more  or  less  noise.     If  a  volcan 
already  exist  in  the  country,  an  eruption  begins  by  pouring  out 
abundant  fumes,  composed  of  various  gases  and  aqueous  vapour, 
then  pulverulent  matter  called  volcanic  ashes,  the  quantity  of  which 
is  sometimes  immense ;  then  follow  directly,  when  they  do  not 
appear  from  the  beginning,  fragments  of  red-hot  porous  stones, 
called  rapilli  or  lapilli  and  pouzzolani,  more  or  less  considerable 
blocks  of  solid  matter,  which  are  sometimes  ejected  to  great  dis- 

27.  What  are  Solfata'ras  ? 

28.  What  is  the  character  of  the  water  of  lakes  found  in  craters  ? 

29.  How  is  the  commencement  of  eruptions  characterized  I     What  are 
volcanic  ashes  ?     What  is  rapilli  ?     What  are  volcanic  bombs  ?     What  is 
tu'fa  ? 


116  VOLCANIC  PHENOMENA.— ERUPTIONS. 

tances ;  and  lastly,  portions  of  melted  matter  torn  from  the  lava 
filling  the  crater,  and  becoming  rounded  by  their  motion  through 
the  air,  form  what  are  called  volcanic  bombs.  From  all  this  we 
have,  amidst  violent  detonations,  immense  bundles  or  masses  of 
various  matters  projected  to  great  heights,  lighted  by  reflection  from 
the  melted  lava,  part  of  which  fall  at  greater  or  less  distances,  ac- 
cording to  their  weight  and  the  force  with  which  they  are  impelled. 
Ashes,  rapilli,  or  pomice  then  produce  in  the  vicinity  of  the  volcan, 
sometimes  even  at  a  distance,  considerable  deposits,  which  becoming 
solid  by  their  weight  and  by  water,  form  what  is  termed  volcanic 
tufa,pumice  tufa,  and  various  conglomerates. 

The  vapours  and  ashes  ejected  from  volcanoes  sometimes  form  enormous 
clouds,  frequently  dense  enough  to  intercept  the  light  of  day,  and  shroud 
the  whole  neighbourhood  in  darkness.  These  clouds,  driven  by  the  wind, 
are  sometimes  carried  to  the  distance  of  twenty,  fifty,  and  even  two  hun- 
dred leagues.  This  happened  in  1812,  when  the  ashes  of  Saint  Vincent,  in 
the  Antilles,  were  carried  to  Barbadoes,  and  so  darkened  the  air  that  persons 
could  not  see  their  way.  The  ashes  of  Vesuvius  were  carried  in  1794  to 
the  end  of  Calabria;  and  it  was  found  even  in  Procopus,  that  during  the 
eruption  of  452  they  were  conveyed  as  far  as  Constantinople. 

What  occurs  at  the  bottom  of  seas  during  eruptions  is  not  seen  ;  but  it  is 
clear  that  the  ejection  of  earthy  matters,  rapilli,  and  pumice,  are  not  less 
abundant,  because  we  find  at  these  times  on  the  surface  enormous  quanti- 
ties of  them,  and  in  land  upheaved,  there  are  seen  distinctly  deposits  of 
volcanic  tufa,  pumice  tufa,  and  conglomerates,  precisely  like  those  formed 
on  land. 

30.  Appearance  of  melted  matters. — The  phenomena  mentioned 
are  sometimes  the  only  effects  of  an  eruption  ;  but  most  generally 
they  are  only  the  precursors  or  sequents  of  the  expulsion  of  melted 
matter,  which  soon  appears  under  different  forms.      Sometimes 
these  matters,  most  frequently  in  mass,  rise  in  cones  or  domes 
above  the  very  orifice  from  which  they  issued,  sometimes  entire, 
sometimes  vertically  perforated  in  the  centre,  sometimes  suscep- 
tible of  being  pushed  further  out.     This  happened  at  Jorullo,  and 
again  and  again  in  the  gulf  of  Santorin,  and  the  same  must  occur 
in  a  great  many  other  localities. 

31.  Under  other  circumstances,  the  crater  first  formed  at  the 
summit  of  a  volcan  is  completely  filled  with  melted  matters  ;  these 
soon  break  a  passage  at  a  greater  or  less  depth,  pouring  out  tor- 
rents, which  furrow  the  side  of  the  mountain,  and  run  to  the 
plain,  where  they  spread  more  or  less. 

32.  Form  of  currents. — If  fissures  or  cracks  of  eruption  be 
formed  at  the  foot  of  a  volcano  in  a  flat  country,  the  lava  escaping 
from  it  at  once  forms  broad  horizontal  sheets  in  the  middle  of  the 
plain.     This  occurred  in  Iceland  in  1783;  crevasses  formed  in  the 
plain  at  the  foot  of  Skaptar-Jokul,  a  high  volcanic  mountain  of  the 

30.  What  is  the  form  of  melted  matters  ejected  from  volcanoes  ? 

31.  How  are  lava-currents  formed? 

32.  What  is  the  form  of  lava-currents  ? 


VOLCANIC  PHENOMENA.— LAVA-CURRENTS.         117 

country,  and  an  immense  volume  of  melted  matter  escaped  from 
them.  This  immediately  spread  over  the  soil,  covering  eighty 
square  leagues,  filling  up  all  depressions,  and  forming  a  vast  lake 
of  fire  of  considerable  depth. 

33.  But  this  is  not  always  the  case ;  the  current  often  forms  on 
more  or  less  inclined  slopes,  and  the  lava  forms  true  currents  on 
their  surface,  of  greater  or  less  length,  a  part  of  which  adheres  to 
the  land  in  consequence  of  cooling,  and  in  evidence  of  its  passage. 
After  its  exit  from  the  bosom  of  the  earth,  the  melted  matter  soon 
cools  an  the  outside,  solidifies,  wrinkling  and  cracking  in  every 
direction,  and  thus  acquires  a  crust,  ordinarily  porous,  the  thickness 
of  which  becomes  more  or  less  considerable.     This  crust  prevents 
the  liquid  or  paste  it  envelopes  from  spreading,  and  confines  the 
current  to  a  certain  thickness ;  also,  from  its  slight  faculty  of  con- 
ducting heat  it  prevents  the  interior  lava  from  cooling,  which,  from 
this  cause,  goes  on  very  slowly.     Lavas  have  in  fact  remained 
liquid  or  pasty,  and  preserved  a  high  temperature  for  a  very  con- 
siderable time ;   some  are  cited  as  still  running  on  very  gentle 
slopes,  ten  years  after  their  ejection,  and  others  which  gave  off 
vapour  twenty-six  years  after  their  exit  from  the  bosorn  of  the  earth. 

34.  If  after  the  external  cooling  the  volcanic  spring  continues 
to  furnish  melted  lava,  the  current  takes  place  in  a  kind  of  con- 
solidated sack  which  is  formed ;  a  sack  which  then  strives,  as  it 
were,  in  all  directions,  is  broken  and  mended  successively ;  this 
causes  the  twisting  and  various  irregularities  in  the  current  of 
lava.     When  the  source  is  stopped,  the  matter  which  escaped  from 
it  does  not  continue  to  flow  the  less  in  the  sack  enclosing  it,  but  the 
latter  successively  flattens,  and  the  middle  is  effaced,  leaving  a 
more  or  less  elevated  roll  or  ridge  on  the  margins.     This  is  first 
seen  at  the  upper  part  of  the  current,  then  successively  to  a  point 
where  the  liquid  matter,  becoming 

more  and  more  viscid,  has  not  suffi- 
cient force  to  drag  after  it  the  solid 
parts  formed,  to  break  or  push  them 
forwards.  The  lava  then  stops  at 
the  bottom  of  the  sack,  terminating  fig.  2QQ.— Lava-current  arrested 
in  a  club-like  mass  (Jig.  200).  The  ^  on  a  sl°Pe- 

form,  direction,  and  extent  of  these  lava-currents  vary  according 
to  circumstances,  such  as  the  degree  of  inclination  of  the  mountain 
sides,  and  the  nature  of  the  lava  itself.  Some  volcanic  products 
are  so  pasty  they  cannot  run,  but  remain  over  the  aperture,  as 
occurs  with  certain  trachytes,  which  then  form  more  or  less  elevated 
domes.  Others,  such  as  various  obsidians,  which  seem  to  cool 
and  harden  quickly,  are  sometimes  arrested  in  form  of  great  tears, 

33.  Do  lava  currents  cool  rapidly  under  all  circumstances  ? 

34.  Is  the  form,  direction,  and  extent  of  lava-currents  always  the  same  ? 


118  VEINS  OF  LAVA,  OR  DYKES. 

even  on  steep  slopes,  as  at  Teneriffe.  On  the  contrary,  stony  lavas 
which  cool  slowly  and  long  remain  fluid,  are  not  arrested  except 
on  a  horizontal  plain. 

35.  Various  characters  of  the  same  lava. — From  what  has  been 
stated,  it  is  certain  that  lavas  cannot  accumulate  to  a  great  thick- 
ness, or  spread  in  sheets,  except  on  a  horizontal  plain.     The  struc- 
ture of  lava  depends,  in  a  degree,  on  its  external  arrangement.     The 
vein,  which  is  behind  -the  current,  on  a  veiy  steep  slope,  is,  in  parts, 
thin,  scoriaceous,  corded,  and  always  very  porous.     On  less  steep 
slopes,  the  surface  of  pieces  is  more  united,  the  pores  are  smaller ; 
on  descents,  at  an  angle  of  from  three  to  five  degrees,  the  dislocated 
parts  are  in  plates  of  greater  or  less  thickness,  the  structure  of 
which  presents  a  certain  uniformity,  and  the  centre  is  sometimes  a 
little  more  compact,  if  the  thickness  is  sufficient.     In  great  flows, 
causing  great  accumulations  on  plains,  where  the  depressions  are 
filled  up,  all  the  inferior  part  becomes  a  compact,  and,  more  or 
less,  crystalline  mass,  which  is  porphyritic,  because  then  it  cools 
slowly  and  tranquilly  ;  in  this  case  it  is  frequently  divided,  through 
its  whole  height,  into  columnar  masses,  generally  normal  on  the 
cooling  surfaces,  and  porous  at  the  upper  part  only ;  this  is  seen 
at  Vesuvius  and  Etna,  where  the  lava  is  very  thick,  and  at  Iceland 
in  the  immense  deposit  formed  by  the  eruption  of  1783. 

36.  Veins  of  Lava,  or  Dykes. — It  frequently  happens,  that  in 
volcanic  eruptions  there  is  formed,  on  the  sides  of  the  mountain, 
crevices  of  greater  or  less  breadth,  through  which  the  lava  comes 
to  the  surface  of  the  soil.     These  cracks  are  remarked  for  a  long 
time  after  their  formation,  either  from  remaining  partly  open,  or 
from  the  rapilli  with  which  they  are  filled,  leaving  a  kind  of  ditch, 
which  may  be  readily  followed.     They  may  be  also  recognised  by 
the  partial  and  crate'riform  excavations  of  these  debris,  which  all 
have  the  same  line  of  direction ;  sometimes  they  are  distinguished 
by  rolls  of  scoria  on  the  edges,  which  escaped  while  the  lava  was 
boiling  in  the  interior;  they  also  exhibit  conduits  of  lava,  which 
unite  to  each  other  the  different  cones  of  eruption  formed  on  their 
line  of  direction.     It  cannot  be  doubted  that  these  cracks  remain 
partly  filled  with  the  lava  to  which  they  gave  passage,  giving  rise 
to  veins,  or  dykes.     Sometimes  the  lava  flows  above  the  crack  or 
fissure,  forming  sheets  on  the  surface.     Sometimes  a  coat  or  bed 
of  lava  is  found  in  evident  communication  with  a  dyke,  which, 
after  having  passed  up  through  all  the  lower  deposits,  stops  in- the 
middle  of  it  (Jig.  201) ;  and  it  is  not  rare  to  find  several  beds  of 
lava  lying  one  above  the  other,  each  one  corresponding  with  a  par- 
ticular dyke  (fig.  202),  to  which,  no  doubt,  it  owes  its  origin ;  the 

35.  Are  the  characters  of  lava  always  the  same  ? 

36.  What  are  dykes  ?     Are  all  dykes  precisely  the  same  in  character  ? 


GASEOUS  VOLCANIC  PRODUCTS.  119 

most  recent  of  these  dykes  or  veins  being  the  one  which  has  passed 
up  through  all  the  inferior  beds  or  tables,  to  form  the  upper  one. 


Fig.  201.  Fig.  202. 

Sheets,  or  tables  of  Lava,  with  their  corresponding  Dykes. 

37.  The  matter  that  constitutes  dykes  is  rarely  porous,  except 
sometimes  on  the  sides  towards  the  rock  encasing  it ;  it  is  fre- 
quently even  of  a  finer  grain  than  the  table  or  bed  in  which  the 
dyke  terminates ;  its  mass  is  sometimes  divided  into  prisms  per- 
pendicular to  the  sides  of  the  fissure,  which  were  the  cooling  sur- 
faces.    This  matter  generally  re- 

sists  atmospheric  influences,  and 
it   frequently   happens   that   the 
surrounding  rock  being  degraded, 
carried  away  by  external  agents,  f 
the  dyke  remains  projecting  on 

the  side  of  the  escarpment  (jig-      

203),  or  even  rising  out  of  the  Fig-.  203.— Dyke  brought  into  view  by 
earth  like  a  wall.  destruction  of  surrounding  rocks. 

38.  Gaseous  volcanic  products. — Volcanic  phenomena  are  ac- 
companied by  the  production  of  great  quantities  of  various  gases, 
some  permanent,  others  condensable  or  soluble.     These  products 
consist  for  the  most  part  of  watery  vapour ;  but  they  are  found  to 
contain  also  various  acids,  and  other  matters  sublimated  from  the 
volcano.     Most  of  these  gases  are  fatal  when  breathed. 

Gases,  always  at  a  high  temperature  and  mixed  with  the  vapour  of  water, 
act  powerfully  on  the  solid  surrounding-  matters ;  they  disaggregate  and 
decompose  them  in  all  ways,  reduce  them  to  powder,  to  mud,  and  form  new 
compounds  of  every  kind.  This  happens  in  all  solfata'ras,  where  it  is  often 
necessary  to  be  cautioned  against  falling  into  masses  of  muddy  matter, 
which  is  sometimes  very  hot.  But  nothing  is  comparable  in  this  respect  to 
the  volcans  of  Java;  the  acid  and  aqueous  vapours  which  are  there  in  great 
abundance,  destroy  the  rocks  and  form  a  paste  of  them,  which  speedily 
becomes  incapable  of  resisting  the  explosive  action  of  the  interior.  These 
fearful  eruptions  take  place,  not  of  lava  as  in  ordinary  volcanoes,  but  of 
enormous  masses  of  boiling  water,  charged  with  sulphuric  acid  and  thick 
mud,  which  destroy  everything  in  their  way,  and  cover  the  whole  country 
with  a  sulphurous  slime  the  matter  of  which  is  called  buah.  This  happened 
in  1822,  on  the  eruption  of  Gallung-Gung,  which,  with  earthquakes  and 
horrible  noises,  was  considerably  sunk,  truncated  at  the  summit,  and  entirely 
overturned.  Torrents  of  hot  sulphurous  water  and  mud  issued  from  rents 

37.  What  is  the  character  of  the  matter  constituting  dykes  ?     By  what 
means  are  dykes  sometimes  naturally  brought  into  view  ? 

38.  What  are  the  characters  of  the  gaseous  products  of  volcanoes?    How 
do  gases  affect  surrounding  solids  ?      Do  volcanoes  ever  eject  mud  1     In 
what  condition  is  lava  when  gases  are  disengaged  from  it  ? 


120  SOLID  VOLCANIC  PRODUCTS. 

in  the  side  of  the  mountain ;  and  many  inhabitants  were  swept  away  in  the 
waters,  or  buried  under  deposits  of  mud,  during  the  8th  and  12th  days  of 
October. 

Muddy  eruptions  of  Quito. — The  volcans  of  Peru,  which  like  those  of  Java 
have  rarely  produced  lavas,  vomit  from  their  sides  torrents  of  mud  called 
rwoya,  sometimes  sulphurous  like  the  luah  of  Java,  at  others  carboni'ferous. 
This  happened  in  1698,  when  the  volcan  of  Carguarai'zo  crumbled,  covering 
more  than  2500  square  miles  with  mud  ;  and  in  1797,  when  the  village  Pel- 
lile'o,  near  Rio-Bamba,  was  buried  under  a  mass  of  black  mud,  &c.  What 
especially  characterizes  the  eruptions  in  Peru,  and  makes  them  very  strange, 
is  that  the  muddy  waters  which  spring  from  the  bosom  of  the  earth,  are 
filled  witli  small  fishes,  species  of  which  live  in  the  neighbouring  lakes;  and 
the  quantity  of  them  has  been  sometimes  so  great  as  to  excite  epidemic  dis- 
eases by  their  putrefaction. 

Gases  disengaged  from  Lavas. — It  can  be  readily  conceived  that  gases 
and  matters  of  various  kinds  may  be  disengaged  from  the  bowels  of  the 
earth,  through  fissures  communicating  with  its  surface ;  but  what  is  most 
remarkable,  they  are  also  disengaged  from  lavas,  although  on  leaving  the 
volcano  they  have  no  properties  in  common.  As  long  as  the  lava  is  fluid 
and  at  a  high  temperature  nothing  escapes  from  it,  but  the  moment  it  begins 
to  harden,  and  consequently  to  cool,  gases  are  disengaged  in  more  or  less 
quantity.  Streams,  matters  which  filled  the  lowest  levels,  then  constantly 
emit  the  vapour  of  water,  hydrochloric  acid,  sal  ammoniac,  which  are  de- 
posited on  the  snrface,  to  say  nothing  of  realgar,  iron,  &c.,  which  are  some- 
times sublimed  in  the  fissures  or  cracks.  Consequently  the  lava  itself  must 
contain  these  matters,  which  remain  engaged  in  it,  we  know  not  how,  while 
the  mass  is  fluid  or  pasty,  and  which  are  disengaged  just  in  proportion  as 
it  solidifies  and  cools,  and  in  a  manner  which  leaves  no  after-trace.  It  is 
supposed  that  all  these  matters  give  to  porous  lavas,  the  power  of  preserving 
their  fluidity  for  a  much  longer  time  than  similar  substances  artificially 
prepared. 

39.  Solid  products  of  Volcanoes. — All  the  solid  substances  which 
volcanoes  produce  in  great  abundance,  belong  to  the  group  of  si'li- 
cates,  generally  anhy'drous  si'licates,  and  particularly  to  that  divi- 
sion of  those  confounded  under  the  name  of  feldspar.  These  are 
generally  compound  rocks,  and  substances  more  or  less  mixed,  the 
principal  base  of  which  it  is  difficult  to  separate,  and  therefore 
they  cannot  be  accurately  classified :  we  are  forced  to  resort  to 
artificial  divisions. 

1st.  7'rdc/n/te  (from  the  Greek  trachus,  rough)  is  a  rock  often 
rough  to  the  touch,  as  its  name  indicates,  composed  of  albite  or 
rya'colite,  sometimes  compact,  of  a  ceroid  or  vitreo-resinous,  and 
occasionally  earthy  lustre,  sometimes  crystalline,  the  mass  being 
finely  porous,  containing  crystals  of  the  same  substances,  and  often 
also  hornblende  and  black  mica. 

Albite  (from  the  Latin,  o/feus,  white),  a  mineral  so  called  from  its  colour, 
which  contains  si'lica,  alu'mina,  and  soda.  A  lamellar  variety  is  found  at 
Chesterfield,  Mass.,  called  Cleavelandite,  in  honour  of  Professor  Cleaveland. 

Rya'colite  (from  the  Greek,  ruax,  a  stream,  and  lithos,  stone),  is  a  glassy 
mineral,  of  a  greyish-yellow  to  white  colour,  or  colourless.  Besides  si'lica, 
alu'mina,  and  soda,  rya'colite  contains  potash. 

39.  What  are  the  general  characters  of  the  solid  products  of  volcanoes  ? 
What  is  tra'chyte  ? 


SOLID  VOLCANIC  PRODUCTS.  121 

Hornblende  (from  the  German),  a  kind  of  dark  or  black  variety  of  mine- 
ral, belonging  to  the  same  group  as  tre'molite,  acti'nolite,  asbe'stus,  &c. 

Mi'ca  (from  the  Latin,  mico,  I  shine),  is  a  mineral  generally  found  in 
thin,  elastic  laminae,  soft,  smooth,  and  of  various  colours  and  degrees  of 
transparency.  It  is  one  of  the  constituents  of  granite  and  its  associate 
rocks. 

40.  2d.  Obsi'dian  (from  the  Greek,  opsis,  view,  or  after  Obsi- 
dius,  who  first  found  it  in  Ethiopia},  is  a  homogeneous,  vitreous 
substance  of  various  colours.     By  me  ancients  it  was  used  in. 
place  of  glass,  and  is  also  called  volcanic  glass.     It  consists  of  si'li- 
ca,  alu'mina,  with  a  little  potash  and  oxide  of  iron. 

This  substance  is  produced  abundantly  in  the  islands  of  Lipari 
and  Teneriffe,  the  volcans  of  the  Andes,  and  wherever  volcanic 
apertures  open  in  tra'chyte. 

41.  3d.  Compact  lava.     A  substance  with  a  compact  base  of  a 
deep  colour,  most  frequently  formed  of  labradorite,  containing  crys- 
tals of  the  same  substance,  or  of  the  feldspa'thic  group  in  general, 
which  in  the  mass  presents  a  more  or  less  distinct  porphyritic  struc- 
ture.    Crystals  of  py'roxene,  of  am'phibole,  black  mica  and  peri- 
dote  are  also  occasionally  found. 

La'bradorite — Labrador  spar.  A  beautiful  variety  of  opalescent  feldspar 
from  the  coast  of  Labrador  :  it  exhibits  brilliant  and  mutable  tints  of  blue, 
red,  green  and  yellow,  and  is  susceptible  of  a  good  polish.  It  is  cut  into 
small  slabs,  and  employed  in  ornamental  jewelry.  It  is  a  si'licate  of  alu'- 
mina,  lime,  and  soda,  with  traces  of  oxide  of  iron. 

Py'roxene  (from  the  Greek,  pur,  fire,  and  zenos,  stranger).  The  augite, 
supposed  to  have  pre-existed  in  the  volcanic  minerals  containing  it,  and  riot 
to  have  been  formed  by  fire. 

Am'phibole  (from  the  Greek,  amphibolos,  equivocal).  A  name  applied  by 
some  mineralogists  to  hornblende,  because  it  may  be  mistaken  for  augite. 

Peridote,  or  Chrysolite  (from  the  Greek,  chrusos^  gold,  and  lithos,  stone), 
from  its  colour.  The  topaz  of  the  ancients. 

These  substances  constitute  the  centre  of  thick  currents,  the  in- 
ferior part  of  the  mass  formed  in  excavations  or  hollows ;  they  are 
often  divided  into  prismatic  columns. 

42.  4th.  Porous,  or  scoria'ceous  lava.     A  substance  of  the 
same  nature  as  the  preceding,  but  rarely  having  crystals  embedded 
in  it,  and  its  structure  is  porous,  or  cellular.     These  lavas  consti- 
tute the  upper  parts  of  thick  layers,  and  envelope  lava  currents 
and  streams  which  rest  on  the  surface  of  the  ground. 

43.  5th.  PoKzzolani,  volcanic  tufa.     Masses  of  small  scoria'- 
ceous fragments,  or  rapilli,  accumulated  around  volcans,  or  earthy 
substances,  which  contain  them  in  greater  or  less  quantity.     Pu- 
mice-tufas are  formed  of  fragments  of  pumice,  and  trdchytic  con- 
glomerates of  fragments  of  tra'chyte,  unite'd  by  crystalline  or  earthy 
cement. 

40.  What  is  obsi'dian  ?  41.  What  is  compact  lava? 

42.  What  is  scoria'ceous  lava  ?  43.  What  is  volcanic  tufa  ? 

11 


122  EFFECTS  OF  WATER. 

44.  6th.  To  these    may  be  added   scoriee  in   tears,  irregular 
stala'ctites   scattered  on   the   surface  of  volcanoes,  and   volcanic 
bombs,  which  are  sometimes  found  at  considerable  distances. 

45.  Volcanoes  furnish  annually  but  a  small  quantity  of  materials 
to  the  solid  crust  of  the  globe,  and  the  upheavals  they  cause  pro- 
duce very  slight  change  in  the  elevation  of  countries  where  their 
action  is  manifest.     Nevertheless,  if  we  remember  that  a  great 
number  have  been  in  action  since  the  time  of  history,  and  observa- 
tion shows  that  a  great  many  more  were  previously  in  action,  we 
are  led  to  the  conclusion  that  volcanic  substances  are  important, 
and  their  presence  must  have  occasioned  great  modifications  on 
the  surface  of  our  planet. 


LESSON  VII. 

INFLUENCE  OF  EXTERNAL  AGENTS  ON  THE  SURFACE  OF  THE  EARTH. 
— Effects  of  the  Atmosphere — Degradation — Effects  of  Winds 
— Dunes — Effects  of  Lightning. 

EFFECTS  OF  WATER.  —  Dissolving  power — Softening  power — 
Denudation — Erosion — Effects  of  weight  of  Water — Punning 
Waters — Debacle  of  Lakes — Mud-torrents — Slope  of  Torrents 
and  Rivers — Rolled  Flints — Transportation  by  Ice  and  Gla- 
ciers— Action  of  Waves— Deposits  formed  by  Water — Geysers 
—  Structure  of  sedimentary  Deposits — 7a'lus  —  Effects  of 
Transport  or  Drift — Effects  of  oscillation  in  Waters — Nature 
of  Deposits  from  Water — Coral  Reefs  —  Polypa'ria  —  Peat- 
bogs. 

1.  Atmospheric  Effects.  —  Variations  of  temperature,  the  air, 
winds,  dryness,  and  moisture,  act  very  perceptibly  on  most  mine- 
ral substances  ;  there  is  not  a  rock  on  the  surface  of  the  earth  which 
does  not  present  an  appearance,  externally,  totally  differing  from 
what  is  seen  internally,  when  it  is  broken.  This  is  everywhere 
seen  in  escarpments  formed  by  making  roads,  in  mountainous 
countries,  where  it  is  necessary  to  cut  through  rocks ;  the  exterior 
is  discoloured,  and  more  or  less  extensively  disaggregated,  corn- 
pared  with  the  freshly-exposed  interior.  These  effects  are  not 
solely  produced  by  a  great  lapse  of  time  ;  a  few  years  are  sufficient 
for  them  to  be  shown,  not  only  on  the  surface,  but  to  considerable 
depths  :  these  effects  are  seen  in  ancient  quarries  of  marble,  or  of 

44.  What  other  solids  are  produced  by  volcanoes  ? 

45.  What  influence  do  volcanoes  exert,  on  the  elevation  of  countries  ? 

1.  How  are  the  effects  of  the  atmosphere  on  rocks  manifested?  How 
does  frost  act  on  rocks  ?  Is  a  very  long  period  of  time  necessary  for  the 
atmosphere  to  produce  its  effects  on  rocks  ? 


ATMOSPHERIC  EFFECTS.  123 

certain  granites,  and  in  dressed  stone.  The  effect  is  more  rapid 
and  perceptible,  in  proportion  to  the  susceptibility  of  the  substance 
to  imbibe  moisture,  and  to  dry  again ;  alternations  which  produce 
a  very  rapid  disaggregation,  when  frequently  repeated,  as  is  gene- 
rally the  case  in  mountains.  The  substances  which  degrade  most 
easily,  are  those  of  a  granular  structure,  either  earthy  or  crystalline ; 
those  of  a  foliated  structure ;  or  compact  masses,  fractured  and 
split  on  the  surface,  such  as  are  often  seen  in  mountains.  Frost, 
when  it  attacks  water  absorbed  by  a  body,  is  also  a  powerful  cause 
of  destruction,  because  the  expansion  consequent  upon  it  produces 
a  multitude  of  cracks  in  all  directions.  As  long  as  the  cold  con- 
tinues, its  parts  are  held  together  by  ice  as  by  a  cement ;  but  when 
a  thaw  comes,  the.  whole  falls  in  scales,  grains,  or  dust. 

Mountains  cannot  be  visited  without  meeting'  evident  traces  of  degrada- 
tion of  this  kind.     In  limestone  escarpments  (Jig.  204),  we  see  parts  of  loose 


Fig.  204.  Fig.  205. 

Daily  effects  of  degradation  in  mountains. 

texture,  more  or  less  hollowed  out,  and  the  more  solid  banks  remain.  Hence 
the  falling  of  the  latter,  which  are  successively  detached  in  more  or  less 
voluminous  blocks.  In  high  mountains  (fig.  205),  often  formed  of  in- 
clined  strata,  which  present  their  cuts  or  planes  to  the  slope,  we  observe  the 
most  marked  degradations ;  parts  are  constantly  detached,  particularly  at 
times  of  most  sensible  atmospheric  variations;  at  the  instant  of  thaw,  enor- 
mous avalanches  of  stones  occur,  and  roll  down  the  sides  with  astonishing 
rapidity,  sweeping  everything  in  their  course  ;  sometimes  great  blocks,  and 
considerable  portions  of  the  mountain  fall  with  tremendous  noise.  Hence 
the  enormous  debris  which  accumulate  at  the  base,  sometimes  covering  a 
great  extent 

2.  Degradations  attributable  to  these  effects. — The  degradation 
which  many  rocks  present  is  generally  attributed  to  atmospheric 
influences,  lo  g  continued.  Almost  all  rocks,  in  fact,  are  more  or 
less  deeply  changed,  and  are  in  a  state  of  much  less  solid  aggrega- 
tion, much  less  homogeneous,  on  the  surface,  than  they  are  inter- 
nally. In  almost  all  quarries,  it  is  necessary  to  remove  a  great  mass 
of  matter,  before  obtaining  blocks  which  are  homogeneous,  solid, 
free  from  cracks,  and  possessed  of  the  bright  colours  which  are 
ordinarily  sought;  this  is  especially  the  case  with  marble,  and 
generally,  also,  with  compact  limestone.  Certain  granites  are  so 
deeply  disintegrated,  that  the  whole  surface  of  the  soil  presents  a 

2.  What  is  meant  by  degradation  of  rocks  ?    What  are  rocking  stones  ? 


124 


ACTION  OF  WINDS.— DUNES. 


mass  of  gravel  in  rounded  hills,  gullied  by  the  rain  in  all  directions. 
Frequently  we  find  these  granites  on  the  surface  of  the  soil,  in 
great  rounded  blocks,  piled  up  one  on  the  other  (Jig.  206),  in  the 
strangest  manner,  sometimes  in  unstable  equilibrium,  and  suscep- 


Fig.  206. — Degradation  of  granite  as  seen  in  different  places. 

tible  of  oscillating  from  the  slightest  effort ;  these  are  termed  rock- 
ing stones,  in  some  localities. 

In  mountains  where  the  granite  is  easily  decomposed,  we  often  remark 
that  the  mass,  more  or  less  cut,  is  in  a  sort  of  horizontal  stories,  divided  by 
vertical  fissures,  so  as  to  present  a  kind  of  agglomeration  of  irregular  paral- 
le'llipipeds.  It  is  supposed  that,  in  consequence  of  atmospheric  influences, 
these  angular  blocks  are  altered  on  their  faces  and  angles  ;  that  the  disag- 
gregated parts  are  successively  detached,  producing  rounded  masses,  piled 
on  each  other  like  cheeses,  as  we  now  see,  sometimes,  isolated  on  the  surface 
of  the  soil. 

3.  Action  of  winds — dunes.  Although  winds  act  but  very 
feebly  on  solid  mineral  masses,  they  exert  an  important  influence 
on  deposits  of  fine  movable  sands.  We  know  that  in  the  deserts 
of  Africa  and  Arabia,  the  winds  raise  immense  clouds  of  burning 
sands,  conveying  them  from  place  to  place,  and  suddenly  produc- 
ing vast  hills,  sometimes  quite  high,  which  a  new  gale  again  de- 
stroys. All  sandy  sea-coasts  are  exposed  to  similar  effects ;  the 
least  gale  sets  the  sands  in  motion,  and  produces,  on  the  previously 
uniform  surface,  a  multitude  of  wrinkles  or  ridges,  parallel  to  each 
other,  separated  by  a  greater  or  less  interval,  and  each  presenting 
a  gentle  slope  towards  the  wind,  and  a  more  abrupt  declivity  on  the 
opposite  side,  as  represented  (fig.  207);  the  next  gust  of  wind  sets 
all  these  ridges  in  motion,  and  each  one  is  soon  found  to  occupy  the 
space  which  separated  it  from  the  preceding  ridge.  This  pheno- 
menon of  dunes,  or  downs,  is  seen  in  miniature  on  the  sea-beaches ; 
and  they  sometimes  invade  immense  tracts  on  adjacent  planes. 
These  hills,  placed  one  behind  the  other,  in  a  direction  perpendicu- 
lar to  that  of  the  prevailing  winds,  are  constantly  in  motion,  and 
constantly  advance  towards  the  interior  of  the  land ;  the  wind  from 

3.  What  are  dunes  ?  How  are  they  formed?  What  is  meant  by  talus  ? 
At  what  rate  do  dunes  advance  ? 


EFFECTS  OF  WATER.  125 

seaward  drives  the  sand  from  the  foot  of  the  hillock  (fig.  207,  a), 
to  its  summit  (6),  whence  it  falls  in  the  line  /;,  c,  forming  at  this 
point  a  falling  talus,  always  more  abrupt  than  the  first  or  rising 


Fig.  207.  Fig.  208. 

Progress  of  dunes,  or  moving  sands. 

ta'lus.  The  result  of  this  is  a  single  hillock,  a  b  c,  taken  sepa- 
rately (fig.  "ZOS),  which  grows  behind,  if  new  sands  be  furnished 
in  front,  or  it  is  displaced,  if  the  same  sands  are  continually  re- 
moved. Now,  the  wind  acting  on  all  these  hillocks  at  the  same 
time,  the  mass  formed  by  them  is  found  to  have  moved  a  certain 
di-stance  inland,  in  a  short  time,  while  new  heaps  are  formed  in 
front,  at  the  expense  of  the  sands  freshly  washed  up  from  the  sea. 
It  is  calculated  that  dunes  advance,  in  this  way,  twenty  or  thirty 
yards  a  year;  so  that  it  is  evident  there  must  have  been  a  time  when 
they  were  far  from  the  places  they  have  invaded.  A  great  many 
localities  are  known,  which  have  been  submerged  by  these  seas  of 
sand. 

4.  Lightning  sometimes  produces  remarkable  effects  ;  in  a  great 
many  places  and  on  various  rocks,  traces  of  fusion  by  thunderbolts 
in  high  mountains  have  been  observed.     According  to  the  observa- 
tions of  Friedler,  when  lightning  penetrates  sand,  it  often  forms 
narrow,  irregular  canals  to  a  great  depth,  the  sides  of  which  are 
consolidated  by  the  fusion  of  quartz  itself;  and  there  are  instances 
where  considerable  portions  of  rocks  have  been  turned  round,  torn 
from  their  places  and  hurled  to  great  distances  by  lightning. 

5.  Effects  of  Water. — Water  plays  a  very  important  part  in  the 
changes  which  are  taking  place  on  the  surface  of  the  globe  ;  some- 
times by  its  dissolving  power,  but  more  frequently  by  its  softening 
action,  its  weight,  and  especially  by  the  motion  that  may  be  com- 
municated to  it,  and  by  the  transporting  power  resulting  from  its 
rapidity.     The  extent  and  importance  of  modifications  from  this 
agent  ought  to  be  understood. 

6.  Dissolving  power. — Water  exerts  a  chemical  action  an  some 
substances  which  it  dissolves,  either  directly  or  by  means  of  the 
carbonic  acid  it  may  contain.     It  acts  directly  on  some  salts  which 
it  meets  here  and  there,  or  on  some  deposits  of  sulphate  of  lime, 
which  it  corrodes  in  various  ways.     When  more  or  less  charged 
with  carbonic  acid  it  acts  on  calcareous  rocks,  either  under  ground 
or  where  they  crop  out  on  the  surface  ;  or  in  high  mountains  at  the 
time  snows  are  melting.     In  this  case,  the  water  generally  pos- 
sesses itself  of  the  carbonic  acid  contained  in  the  air,  in  greater 

4.  What  are  the  effects  of  lightning  on  rocks  ? 

5    By  what  properties  does  water  produce  its  effects  on  rocks  ? 

6.  What  effects  result  from  the  dissolving  power  of  water  ? 


126  EFFECTS  OF  WATER. 

quantity  than  at  other  times,  in  consequence  of  its  low  temperature  ; 
and  running  over  calcareous  masses,  it  forms  furrows  which  gra- 
dually deepen,  and  sometimes  cause  very  considerable  falls  of  rock. 
These  slow  effects  of  water  are  particularly  remarked  in  the  Alps 
and  Pyrenees,  where  the  snows  remain  a  part  of  the  year,  and 
melt  by  degrees  in  the  fine  season. 

7.  Softening  power. — Water,  by  penetrating  argilla'ceous  beds, 
sometimes  softens  them  so  much,  that  they  cannot  remain  on  the 
slopes  they  occupied,  and  fall  from  their  own  weight ;  this  is  the 
cause  of  many  falls  or  slides  in  sedimentary  formations.     One  of 
the  most  remarkable  catastrophes  of  this  kind  happened  in  1806 
at  Ruffiberg  or  Rossberg  in  Switzerland,  after  a  very  rainy  sea- 
son.    The  argillaceous  matters  which  cemented  the  rolled  flints 
forming  the  mountain  becoming  softened,  a  mass  of  more  than 
50,000,000  of  cubic  yards  was  suddenly  detached,  and  precipitated 
into  the  valley,  forming  in  it  hills  sixty  yards  high,  and  burying 
several  villages  under  masses  of  mud  and  flints.     We  often  see, 
on  a  small  scale,  thick  beds  of  rock  gently  slide  to  the  bottom  of 
valleys,  on  softened  argilla'ceous  beds  which  supported  them,  and 
tranquilly  displace  plantations  and  even  the  inhabitants  on  them, 
without  the  proprietors  perceiving  it  at  the  first  moment. 

8.  Waters  which  filter  through  rocks  to  argilla'ceous  layers 
which   may  arrest  them,  and  on  the  plane  of  which  they  are 
directed  to  the  surface,  sometimes  soften  these  substances  also, 
carrying  away  parts  successively,  and  especially  sands  that  may- 
rest  on  them,  laying  bare  in  this  way  underlying  beds :  this  is 
termed  denudation.     There  results  from  this,  at  the  point  where 
the  water  breaks  forth  from  the  declivity  of  hills,  mo're  or  less  ex- 
tensive voids,  which  leave  the  solid  superposed  masses  without 
support,  which  are  then  dislocated  in  different  ways  (fig-  209)  and 


Fig.  209.  Fig.  210 

Escarpments  produced  by  the  action  of  water. 

soon  overthrown.  This  is  frequently  seen  in  certain  escarpments, 
at  the  base  of  which  are  found  argilo-arena'ceous  layers  which  con- 
duct the  springs  externally. 

7.  What  are  the  effects  of  the  softening  power  of  water  on  rocks  ? 

8.  What  is  meant  by  denudation  ? 


EFFECTS  OF  WATER.— FALLS  OF  NIAGARA.          127 

9.  Erosion. — Something  analogous  happens  when  waters,  which 
washing  the  foot  of  a  mountain,  meet  there  with  substances  that 
they  can  easily  soften  or  disaggregate.  These  substances  being 
destroyed,  the  upper  parts  of  the  soil  are  soon  undermined,  and 
more  or  less  considerable  falls  occur.  This  takes  place  on  sea- 
coasts,  on  the  shores  of  lakes  or  rivers  where  more  or  less  elevated 
escarpments  are  formed,  and  more  and  more  degraded.  The 
same  thing  happens  sometimes  at  the  foot  of  cascades  which  fall 
over  rocky  peaks  (Jig.  210),  forming  alternately  calcareous  and 
argilla'ceous  deposits  ;  the  latter  are  disaggregated,  and  borne  away 
little  by  little  by  the  waters  which  exude  on  the  parietes  or  jet 
forth  after  the  fall,  and  other  layers  being  undermined  must  fall 
sooner  or  later  from  their  own  weight.  In  this  case  the  cascade 
cuts  deep  into  the  soil,  and  the  same  being  successively  repeated, 
necessarily  forms  a  gorge  or  bed  the  whole  length  of  the  rivulet, 
which  deepens  more  and  more.  It  is  in  this  way  that  the  falls  of 
Niagara,  by  which  the  waters  of  lake  Erie  are  precipitated  into 
those  of  lake  Ontario,  have  sensibly  receded  since  the  discovery 
by  Europeans,  and  probably  have  excavated  the  deep  bed  through 
which  they  afterwards  escape. 

"  The  waters,  after  cutting  through  strata  of  limestone,  about  fifty  feet 
thick  in  the  rapids,  descend  perpendicularly  at  the  falls  (of  Niagara)  over 
another  mass  of  limestone  about  ninety  feet  thick,  beneath  which  lie  soft 
shales  of  equal  thickness,  continually  undermined  by  the  action  of  the  spray, 
driven  violently  by  gusts  of  wind  against  the  base  of  the  precipice.  In, 
consequence  of  this  disintegration,  portions  of  the  incumbent  rock  are  left 
unsupported,  and  tumble  down  from  time  to  time,  so  that  the  cataract  is 
made  to  recede  southwards.  The  sudden  descent  of  huge  rocky  fragments 
of  the  undermined  limestone  at  the  Horse-Shoe  Fall,  in  1828,  and  another 
at  the  American  Fall,  in  1818,  are  said*  to  have  shaken  the  adjacent  country 
like  an  earthquake.  According  to  the  statement  of  our  guide  in  1841, 
Samuel  Hooker,  an  indentation  of  about  forty  feet  has  been  produced  in  the 
middle  ledge  of  limestone  at  the  lesser  fall,  since  the  year  1815,  so  that  it 
has  begun  to  assume  the  shape  of  a  crescent,  while  within  the  same  period 
the  Horse-shoe  Fall  has  been  altered  so  as  less  to  deserve  its  name.  Goat- 
Island  has  lost  several  acres  in  area  in  the  last  four  years  (prior  to  1841) ; 
and  I  have  no  doubt  that  this  waste  neither  is,  nor  has  been,  a  mere  temporary 
accident,  since  I  found  that  the  same  recession  was  in  progress  in  various 
other  waterfalls  which  I  visited  with  Mr.  Hall,  in  the  state  of  New  York. 
Some  of  these  intersect  the  same  rocks  as  the  Niagara — for  example  the 
Genesee  at  Rochester  ;  others  are  cutting  their  way  through  newer  forma- 
tions— Allan's  creek,  below  Le  Roy,  or  the  Genesee  at  its  upper  falls  at 
Portage.  Mr.  Bakewell  calculated  that,  in  the  forty  years  preceding  1830, 
the  Niagara  had  been  going  back  at  the  rate  of  about  a  yard  annually  ;  but 
I  conceive  that  one  foot  per  year  would  be  a  much  more  probable  conjecture, 
in  which  case  35,000  years  would  have  been  required  for  the  retreat  of  the 
falls  from  the  escarpment  of  Queenston  to  their  present  site,  if  we  could 
assume  that  the  retrograde  movement  had  been  uniform  throughout.  This, 
however,  could  not  have  been  the  case,  as  at  every  step  in  the  process  of 
excavation,  the  height  of  the  precipice,  the  hardness  of  the  materials  at  its 

9.  What  is  meant  by  erosion  ?    What  are  the  effects  of  erosion  ? 


128  ACTION  OF  RUNNING  WATERS. 

base,  and  the  quantity  of  fallen  matter  to  be  removed,  must  have  varied. 
At  some  points  it  may  have  receded  much  faster  than  at  present,  at  others 
much  slower ;  and  it  would  be  scarcely  possible  to  decide  whether  its  ave- 
rage progress  has  been  more  or  less  rapid  than  now." — LyelVs  Travels  in 
North  America. 

10.  Effects  of  weight. — Water  acting  by  its  own  weight  like 
other  bodies,  evidently  often  contributes  to  such  land-falls  as  we 
mention,  and  also  exerts  a  powerful  action  on  the  dykes  and  bar- 
riers which  retain  it.     We  see  the  unhappy  effects  of  inundations, 
to  which  certain  countries  are  subject  from  their  vicinity  to  rivers, 
lakes,  or  seas,  retained  by  natural  or  artificial  dykes. 

11.  Action  of  running  waters. — To  the  softening  action  and 
weight  of  waters  is  often  added  a  new  power,  from  the  motion 
they  acquire  by  running  over  steep  descents.     This  force  is  some- 
times prodigious.     The  effects  are  seen  after  storms  which  pass 
over  moveable  substances,  in  the  deep  ravines  found  to  have  been 
excavated.     These  effects  are  in  proportion  to  the  mass  of  water, 
and  the  rapidity  of  its  motion  on  a  particular  point.     When  a  hur- 
ricane or  violent  storm  bursts  on  a  mountain,  the  soil  is  often  found, 
unless  it  consist  of  living  rock,  removed  and  gullied  to  great  depths. 
The  numerous  fissures  on  the  surface  of  rocks  facilitate  the  action 
of  waters,  and  a  considerable  mass  of  fragments  is  soon  detached, 
which  increase  more  and  more  the  destructive  power  of  the  current. 
Then  blocks  of  every  size  are  loosened,  torn  from  the  mountain 
and  transported  to  great  distances,  multiplying  the  effects  ten  or 
even  a  hundred  fold,  in  proportion  to  their  mass  and  rapidity  of 
motion.     Hence  we  have  great  ravines  on  slopes  that  were  pre- 
viously unbroken,  and  an  immense  accumulation  of  debris  at  the 
foot  of  the  mountain,  and  especially  where  the  soil  or  the  swiftness 
of  the  stream  abated.     Torrents  swollen  by  circumstances  of  this 
kind,  or  by  the  sudden  melting  of  snows,  also  produce  frightful 
ravages;  they  sweep  everything  in  their  way,  even  the  living  rock, 
which  they  soon  attack  forcibly  by  the  fragments  and  blocks  they 
swiftly  urge  along.     Nothing  is  more  terrible  than  this  kind  of 
water-course,  and  to  form  an  exact  idea  of  the  effects  one  must  see 
a  gorge  through  which  it  has  passed,  sometimes  rolling  along  rocks 
measuring  ten  or  fifteen  cubic  yards. 

12.  Debacle  of  Lakes. — Lakes  which  sometimes  form  in  valleys^ 
by  avalanches  or  falls  of  land,  constituting  a  barrier  which  retains 
them,  are  most  fearful  in  their  debacle  (sudden  escape  of  their 
waters  from  breaking  of  their  barrier),  in  consequence  of  an  enor- 
mous mass  of  water  rushing  forth  in  a  few  seconds.     Scarcely  does 
a  flow  begin  through  a  few  rents,  before  the  first  opening  rapidly 
enlarges,  and  in  an  instant  the  whole  dyke  is  carried  away.     An 

10.  Does  the  weight  of  water  contribute  to  its  effects  ? 

11.  What  are  the  effects  of  running  waters  ? 

12.  What  is  meant  by  debacle  ?     What  are  the  effects  of  debacle  ? 


SLOPES  OF  TORRENTS  AND  RIVERS.  129 

enormous  volume  of  water  is  then  precipitated  with  extreme  vio- 
lence, and  nothing  can  withstand  the  combined  effects  of  its  mass 
and  rapidity.  All  is  overturned,  and  the  most  solid  rocks,  if  they 
project,  in  the'least,  across  the  direction  of  the  current,  are  instantly 
torn  away,  broken,  and  transported  to  great  distances.  The  clear- 
ing is  so  complete,  at  the  origin  of  the  current,  and  in  the  narrow 
passages  where  the  slope  is  rapid,  that  the  exposed  rock  seems  to 
have  been  cut  by  the  hand  of  man. 

13.  Mud-torrents,  from  one  cause  or  another,  are  also  formed, 
which  are  not  less  terrible  in  their  ravages.     It  sometimes  happens, 
as  in  Ireland,  that  turf-beds  placed  on  a  slight  declivity,  after  being 
swelled,  more  or  less  arched  by  retaining  rain-water  beneath  them, 
cannot  resist  the  first  heavy  shower,  and  are  set  in  motion.     They 
run  then,  in  spite  of  the  consistence  of  the  mud,  and  the  gentleness 
of  the  descent,  with  prodigious  rapidity,  and  sweep  everything 
they  meet.     Under  other  circumstances,  the  rain-waters  soak  in 
loose,  argilla'ceons  substances,  accumulate  in  the*  midst  of  them, 
and,  at  a  certain  moment,  the  dykes  of  the  reservoir  give  way,  and 
a  torrent  of  thick  mud,  filled  with  fragments  of  rock  and  even  blocks, 
suspended  in  the  viscid  mass,  is  formed,  and  rushes  with  fearful 
rapidity,  overturning  everything,  and  cutting  deep  ravines. 

14.  Slopes  of  torrents  and  rivers.  —  The  disastrous  effects  of 
torrents  are  in  proportion  to  the  descent  on  which  they  move  ;  but 
it  does  not  necessarily  follow  that  their  bed  must  have  a  very  con- 
siderable inclination.     The  most  rapid  torrents,  forming  a  continu- 
ous bed  and  carrying  rocks  a  half-yard  in  diameter,  have  a  descent 
of  only  one  or  two  degrees,  and  many  rivers  flow  very  swiftly  on 
a   much   less   slope — a   descent  of  from  three  to  four  minutes 
(sixty  to  a  degree)  is  about  the  limit  for  navigable  rivers. 

15.  Rolled  flints,  or  pebbles. — In  the   ravages  produced,  by 
water-currents,  the  debris  torn  from  mountains  are  transported  to  a 
greater  or  less  distance,  accordingly  as  the  inclination  of  the  soil 
permits  the  current  to  maintain  its  force  for  more  or  less  conside- 
rable distances  ;  but  in  proportion  as  the  slopes  diminish,  the  swift- 
ness decreases,  and  the  larger  blocks  successively  remain  behind, 
at  the  bottom  of  the  valley,  and  then  those  of  smaller  size,  and  suc- 
cessively the  sand  and  mud,  which  are  often  carried  enormous  dis- 
tances.    In  this  rolling  of  different  substances,  the  blocks  and  frag- 
ments sinking  during  their  transportation,  rubbing  against  each 
other  and  against  the  soil,  gradually  lose  their  prominences  and 
angles,  and  in  the  end  become  completely  rounded,  forming  what 
are  termed  rolled  flints,  which  may  be  more  or  less  voluminous. 

1 3.  How  are  mud-torrents  formed  ?     What  are  their  effects  ? 

14.  Upon  what  do  the  effects  of  torrents  depend  ?     What  is  the  rate  of  the 
slope  of  beds  of  rivers  that  are  navigable? 

15.  How  are  rolled  flints  and   pebbles  produced?     W j 
What  is  sand  ?  ^ 

v  OF  THE 

UNIVERSITY 


130  TRANSPORTATION  BY  ICE  AND  GLACIERS. 

All  the  lower  part  of  torrents,  where  the  soil  is  sufficiently  flattened, 
or  the  enkrgement  of  the  valley  permits  the  waters  to  expand, 
diminishing  their  depth,  and  consequently  their  rapidity,  is  gene- 
rally found  covered  with  these  flints,  which  are  sometimes  accumu- 
lated in  immense  quantities,  and  through  which,  in  its  ordinary 
course,  the  stream  meanders  in  different  ways,  in  a  bed  it  forms 
and  often  changes.  Rivers  and  lakes  into  which  torrents  empty, 
and  where  they  consequently  lose  their  swiftness,  are  often  loaded 
with  these  flints ;  and  this  is  the  cause  of  the  constant  elevation  of 
the  bed  of  the  river  Po  (see  page  15).  Gravel  and  -saw/,  which 
are  merely  small  flints,  the  mud  which  results  from  their  friction, 
and  the  earthy  particles  removed,  are  always  transported  far,  either 
immediately  into  lakes,  or  seas,  or  rivers,  which  deposit  them  on 
their  banks,  and  especially  at  their  mouths,  which  they  more  or 
less  obstruct. 

16.  Rolled  flints,  or  pebbles,  are  also  formed  by  the  action  of  the 
waves  on  fallen  'rocks.     In  this  way,  on  the  coasts  of  France  and 
England,  the  silex,  or  flints  of  the  chnlk,  are  rounded,  by  being 
rubbed  against  each  other,  and  constitute  considerable  banks  of 
pebbles  or  shingle.     Something  similar  must  have  taken  place  at 
points  now  far  inland,  where  we  find  blocks  round  and  smooth,  at 
a  short  distance  from  rocks  from  which  they  were  evidently  de- 
tached. 

17.  Transportation  by  ice  and  glaciers. — On  the  shores  of 
northern  seas,  the  ice  envelopes  blocks  and  masses  of  rock,  which, 
at  the  breaking  up,  are  floated  away  on  ice-cakes  in  all  directions, 
and  deposited  here  and  there,  wherever  they  may  ground,  or  fall 
to  the  bottom  of  the  sea.     In  this  way,  in  Canada,  Greenland,  and 
on  the  coasts  of  Nova  Zembla,  &c.,  very  voluminous  blocks  are 
transported  from  one  place  to  another,  and  often  to  very  conside- 
rabFe  distances  from  the  point  of  departure.     There  is  no  doubt 
that  many  small  debris,  embedded  in  the  ice,  are  transported  in  the 
same  way,  and  form  adventitious  deposits  of  more  or  less  extent. 

18.  Glaciers,  that  is,  beds  of  ice  occupying  the  high  valleys  of 
lofty  mountain  chains,  are  also  very  remarkable  means  of  trans- 
portation.     Various   circumstances    (their   great   weight   chiefly) 
keep  these  deposits  in  constant,  though  very  slow  motion,  from 
half  an  inch  to  an  inch  an  hour,  descending  along  the  slopes  on 
\vhich  they  rest ;  now,  the  surface  of  these  glaciers  is  found  to  be 
covered  with  fragments  and  blocks  which  have  fallen  from  the 
surrounding  mountains,  and  the  whole  is  conveyed  from  the  upper 
to  the  lower  part ;  and  blocks,  often  of  enormous  size,  are  carried 

16.  Are  rolled  flints,  or  pebbles,  produced  by  running  water  exclusively? 
What  is  shingle  ? 

17.  How  are  rocks  transported  by  ice  ? 

18.  What  are  glaciers?     At  what  rate   do  they  move?    What  are 
moraines  ? 


ACTION  OF  THE  WAVES  AND  OF  TIDES.  131 

without  friction  to  considerable  distances  from  their  place  of  origin. 
These  debris,  from  several  causes,  always  accumulate  on  the  late- 
ral parts  of  the  glacier,  against  the  side  of  the  valley,  and  fre- 
quently in  the  middle  also,  from  other  valleys  emptying  laterally 
into  it,  from  which  result  long,  slender  hills,  designated  under  the 
term  moraines.  All  these  debris,  having  reached  the  inferior  ex- 
tremity of  the  glacier,  tumble  into  the  valley  on  its  slope,  and  form 
at  its  foot  other  moraines  often  of  considerable  height.  If,  after 
having  increased  for  a  certain  time  in  consequence  of  a  series  of 
cold  summers,  the  glacier  diminishes  again  by  a  succession  of 
warm,  prolonged  summers,  the  moraines  of  different  kinds,  aban- 
doned by  the  ice,  are  left  on  the  soil ;  some  form  dykes,  of  more 
or  less  height,  at  the  bottom  and  across  the  valley,  and  others  long 
lines  on  the  flanks  of  the  valley,  at  a  greater  or  less  elevation. 

19.  It  must  be  borne  in  mind  that  the  slopes  on  which  glaciers 
move  are  always  much  greater  than  those  of  rivers,  and  that  they 
never  descend  at  an  angle  of  less  than  three  degrees.  This  must 
also  be  the  minimum  slope  of  masses  of  debris  resting  on  the  sides 
of  the  valley,  in  consequence  of  the  rapid  melting  of  the  glacier. 
Thus  we  have  a  means  of  distinguishing  the  remains  of  lateral 
moraines  from  deposits  which  may  have  been  made  by  water-cur- 
rents, the  slopes  of  which  are  very  much  less. 

2i).  Striae,  channels,  polishing  of  rocks.  —  Among  the  effects 
produced  by  the  motion  of  a  glacier  loaded  with  debris,  and  moving 
slowly  over  the  exposed  face  of  a  rock,  is  a  rubbing,  wearing,  and 
polishing  of  the  surface  which  is  passed  over.  The  angles  of  the 
rocks  passed  over  are  rounded  ;  deep  undulating  grooves,  nearly 
parallel  and  longitudinal,  are  cut  in  the  surface,  and  the  polished 
surface  of  the  rock  passed  over  is  scratched  with  fine  striae,  even 
when  it  is  of  the  hardest  quartz.  These  effects  are  well  known 
to  be  produced  by  modern  glaciers. 

21.  Action  of  (he  waves  ami  of  fides. — Waves  exert  an  enor- 
mous power,  particularly  where  rocks  are  abrupt  and  directly  ex- 
posed to  the  open  sea.  The  shock  is  sometimes  so  great  that  the 
earth  trembles  beneath  the  feet;  great  blocks  of  stone  are  torn 
up  and  carried  far  inland,  pushed  up  against  the  inclination  of 
the  shore,  sometimes  thrown  up  vertically  on  projecting  points, 
where  they  afterwards  roll  about  like  small  pebbles :  heavy  banks 
of  sand  and  of  shingle  are  often  removed,  and  entire  countries 
have  been  in  a  moment  destroyed. 

Chronology  and  tradition  of  maritime  countries  furnish  numerous  in- 
stances  of  successive  changes,  of  instantaneous  disasters  which  have  oc- 
curred in  a  great  many  localities.  Immense  ones  have  taken  place,  and 
every  day  new  ones  occur  on  low,  sandy  coasts,  bordering  the  sea,  in  many 

19.  What  is  the  least  slope  or  angle  at  which  glaciers  move  ? 

20.  What  effects  are  produced  on  rocks  by  the  movement  of  glaciers 
loaded  with  debris  ? 

21.  What  is  the  effect  of  the  action  of  waves  ? 


132  ACTION  OF  THE  WAVES  AND  OF  TIDES. 

parts  of  the  world  :  we  have  famous  examples  from  the  mouths  of  the  Scheld 
to  the  canal  of  Jutland,  where  the  Bies-Bosch,  the  Harlem  sea,  the  Zuyder- 
Zee,  the  Dollart,  have  been  produced  in  the  extraordinary  irruptions  of  the 
ocean ;  where  numerous  changes  have  taken  place  in  the  islands,  from  the 
Texel  to  the  mouths  of  the  Elbe,  in  the  windings  of  Lymfiord,  or  on  the 
coasts  of  the  Cattegat  and  of  the  Baltic :  immense  cuts,  bays,  and  deep 
gulfs  are  formed  during  tempests,  and  these  are  still  daily  forming  by  the 
ordinary  action  of  the  waves,  which  sometimes  carry  away  banks  of  sand, 
and  sometimes  destroy  the  dykes  they  had  already  formed. 

22.  The  action  of  waves  is  not  confined  to  moveable  soils,  but 
takes  place  on  the  most  solid  rocks ;  and  hence  those  daily  modi- 
fications in  the  enormous  precipices  found  on  the  coasts  of  France, 
England,  and  almost  all  parts  of  the  world.  The  more  abrupt  the 
coast,  the  more  it  is  exposed  to  denudation  from  the  waves,  because 
directly  breaking  them,  the  shock  is  felt  in  all  its  force.  On  flat 
coasts,  on  the  contrary,  the  wave  meeting  with  no  obstacle,  ad- 
vances as  long  as  its  force  lasts,  and  until  its  rapidity  is  sensibly- 
lost  ;  and  it  carries  up  in  sand  and  pebbles  much  more  than  it 
destroys,  even  on  the  most  moveable  soils.  The  natural  disposi- 
tion of  solid  beds  is  sometimes  opposed,  and  at  others  favourable 
to  the  action  of  waves;  it  is  opposed  when  the  beds,  being  uniform 
and  homogeneous,  incline  towards  the  sea ;  because  the  return  of 
the  wave  along  the  slope  or  ta'lus  diminishes  the  action  of  the  suc- 
ceeding wave,  the  remaining  force  of  which  is  spent  in  merely 
ascending  the  plane:  the  waters  are  spattered  only  by  the  crevices 
and  fissures  that  may  exist  in  the  rock.  But  the  same  is  not  the 
case  when  the  soil  presents  an  escarpment  to  the  action  of  the 
waters  (figs.  211,  212):  the  lower  parts,  continually  attacked  by 


Fig.  211.  Fig.  212. 

Action  of  waves  on  abrupt  rocks. 

reiterated  shocks  of  waves,  which  nothing  contributes  to  diminish, 
are  degraded  and  excavated  successively,  and  with  a  rapidity  in 
proportion  to  the  facility  with  which  the  substance  is  disaggregated ; 
the  upper  beds  being  soon  undermined,  are  not  long  in  being  pre- 
cipitated into  the  sea.  In  this  way  considerable  portions  of  coast 
have  been  overturned  at  different  times,  promontories  have  disap- 

22.  Are  all  coasts  equally  subject  to  the  action  of  waves.     What  circum- 
stances diminish  the  effects  of  the  action  of  waves  ? 


ACTION  OF  THE  WAVES  AND  OF  TIDES.  133 

peared,  and  others  have  been  cut  off  and  separated  from  the  main 
land.  These  effects  are  more  rapid  in  places  where  a  deep  sea 
swallows  up  the  detached  blocks,  or  i^  those  where  the  force  of  the 
waves  is  sufficiently  powerful  to  break  up  the  debris,  and  wear 
them  one  against  the  other  and  successively  remove  them,  so  that 
the  foot  of  the  escarpment  always  remains  bare. 

23.  When  masses  of  debris  falling  from  precipices  are  not  im- 
mediately removed,  a  natural  rampart  is  formed  against  the  action 
of  the  waves,  which  break  before 

reaching  the  foot  of  the  escarp- 
ment (Jig-  213);  then  it  is  only 
in  a  long  time  that  the  debris  are 
worn,  rounded,  and  carried  away 
little  by  little,  depending  on  the 
solidity  of  the  rocks  of  which 
they  are  formed.  These  natural 
ramparts  are  imitated  as  much  as 
possible  by  piling  rocks  before 
the  ta'lus  we  wish  to  preserve  on  Fig.  213.— Accumulation  of  debris 
sea-coasts  or  river  banks.  opposing  the  action  of  waves. 

24.  To  the  action  of  waves  must  be  attributed  certain  excava- 
tions frequently  found,  on  a  level  with  the  sea,  in  calcareous  preci- 
pices, as  well,  perhaps,  as  the  arches  of  greater  or  less  height 
which  traverse  certain  promontories.     Nevertheless,  this   action 
does  not  immediately  produce  great  results,  except  on  matters 
easily  disaggregated,  such  as  chalk,  clay,  and  arena'ceous  sub- 
stances, and  it  is  infinitely  slow  on  more  compact  and  harder  sub- 
stances :  in  fact,  there  are  points  where  no  effect  whatever  has 
been  produced  within  historic  times.     The  erosive  power  of  water 
does  not  explain  all  these  facts,  nor  even  the  impetuous  force  of 
waves ;  the  soils  on  which  this  power  is  exerted  are  cracked  in  all 
directions,  either  by  previous  action,  or  at  the  moment  of  earth- 
quakes, accompanied  by  violent  agitations  of  the  sea,  and  it  is 
then  they  yield  to  the  combined  forces  to  which  they  are  exposed. 
By  this  means  we  can  account  for  isolated  rocks,  for  islands  in  the 
vicinity  of  continents,  for  those  great  gaps  through  which  the  sea 
finds  passage,  for  those  groups  of  split  rocks  which  form  shoals  in 
the  midst  of  the  sea,  and  for  all  those  severings  so  common  and 
varied  on  the  coasts  of  France  and  England,  in  numerous  islands 
that  extend  towards  the  North  Sea,  and  in  a  great  many  localities 
(Jigs.  214,  215). 

25.  Deposits  of  detritus  formed  by  wafers. — Although  waters 
continually  degrade  certain  parts  of  the  globe,  they  create  in  a 
measure  new  deposits  proportioned  to  those  they  remove.     Tor- 

23.  What  circumstance  protects  coasts  from  the  action  of  waves  ? 

24.  What  effects  are  attributable  to  the  action  of  waves  ? 

25.  How  are  deposits  formed  from  water  ? 

12 


134  ACTION  OF  THE  WAVES  AND  OF  TIDES. 


.  214.  Fig.  215. 

Examples  of  rocks  eroded  and  shaped  by  waters. 

rents,  after  having  torn  away  blocks  and  fragments  of  rocks,  re- 
duced them  to  rolled  flints  or  pebbles,  and  carried  them  to  a  greater 
or  less  distance,  deposit  them,  in  proportion  as  the  swiftness  of  the 
waters  diminishes,  in  the  inferior  parts  of  valleys  they  run  through, 
or  at  their  confluence  with  rivers,  or  in  lakes.  Hence  the  masses 
of  debris,  sometimes  immense,  the  coarse  parts  of  which  are  ce- 
mented by  the  mud,  they  deposit  at  the  same  time. 

26.  Great  rivers,  running  through  valleys  of  little  inclination, 
generally  leave  behind  the  coarser  parts  they  have  received,  and 
only  bear  forward  those  whose  weight  is  in  relation  to  their  force  ; 
but  as  their  slope  diminishes  more  and  more,  becoming  almost  in- 
sensible towards  the  end  of  their  course,  they  deposit  the  matters 
they  carry,  and  in  this   way  generally  elevate  their  bed;   and 
finally  they  even  bar  up  their  passage,  and  divide  into  several 
branches,  each  of  which  cuts  its  way  through  sands.    Rivers  have 
in  this  manner  covered  flat  countries  through  which  they  pass 
with  sand  to  a  considerable  depth  and  extent.     In  great  freshets 
these  sands  are  often  taken  up  again,  transported  from  one  point  to 
another,  forming  islands  in  the  middle  of  the  river,  or  alluvions  on 
one  of  its  banks,  while  the  other  is  hollowed  out.    In  rivers,  lakes, 
or  seas,  these  deposits  become  most  remarkable.     There,  if  the 
current  is  not  rapid  enough  to  carry  the  debris  to  a  distance,  in 
spite  of  the  opposition  of  tranquil  waters,  or  if  the  waves  have  not 
sufficient  force  to  remove  the  sands  and   mud  which  have  been 
deposited;  they  form  deltas  at  the  mouths  of  certain  rivers  (see 
page  16). 

27.  The  sea  itself,  which  in  so  many  places  has  made  breaches 
in  the  main  land,  in  others,  heaves  up  and  accumulates  enormous 
quantities  of  pebbles,  formed  by  the  trituration  of  rocks  fallen  from 
precipices,  or  masses  of  sand  and  mud  produced  by  the  waves,  or 

26.  What  are  the  effects  of  deposits  from  rivers  ? 

27.  What  are  the  effects  of  deposits  from  the  sea  ? 


ACTION  OF  THE  WAVES  AND  OF  THE  TIDES.      135 

brought  down  by  rivers.  In  this  way  banks  and  beaches,  of  greater 
or  less  extent,  are  formed  on  coasts,  the  finer  parts  of  which,  car- 
ried inland  by  the  wind,  form  dunes  (see  page  125).  There  are 
many  places  where,  accumulations  of  this  kind  are  daily  formed, 
and  many  points  of  coast  have  been  invaded  by  deposits  from  the 
sea  from  remotest  times :  sometimes,  by  a  single  irruption,  entire 
kingdoms  have  been  covered  by  sand,  and  fertile  countries  changed 
to  arid  plains,  either  in  extraordinary  tides,  or  in  tempests,  or  by 
the  sudden  displacement  of  waters  consequent  on  earthquakes. 
Low  countries,  exposed  to  these  alluvions,  daily  grow  at  the  .ex- 
pense of  the  waters,  and,  at  certain  points,  this  growth  has  been 
estimated  at  several  yards  a  year.  Bays  and  ports  have  been  filled 
up  in  this  way  ;  buildings  and  towns,  formerly  situated  on  the  sea- 
shore, are  now  far  from  it ;  lakes  have  been  transformed  into 
marshes,  marshes  into  solid  land,  and  islands  joined  to  the  main  by 
sands  deposited  around  them.  The  sea,  in  some  instances,  contri- 
butes to  the  growth  of  deltas. 

28.  Torrents  and  rivers  transport  not  only  mineral  debris,  but 
also  organic  remains,  immense  masses  of  plants,  detached  from 
ravines,  or  by  falls.     Here  and  there  great  masses  of  materials  are 
formed,  especially  in  rivers  which  are  bordered  by  immense  forests. 
Great  deposits  of  debris  of  this  kind  are  formed  in  the  Mississippi 
and  its  tributaries ;  they  there  form  immense  rafts  of  trunks  of  trees, 
interlaced,  which  are  stopped  here  and  there  by  the  sands,  and 
finally  are  buried  under  the  enormous  alluvions  daily  deposited. 
The  mass  of  plants  that  the  river  carries  is  so  considerable,  that  it 
has  been  estimated  at  several  thousands  of  cubic  yards  per  hour. 

29.  Currents  of  the  sea  also  often  transport  immense  masses  of 
various  vegetables,  marine  plants,  and  organic  debris  of  every  kind, 
and  from  all  climates,  which  are  here  and  there  deposited  in  the 
bays  these  currents  meet  in  their  course.     This  is  especially  the 
case  as  regards  the  great  Atlantic  current,  the  Gulf  Stream,  the 
strongest  and  most  considerable  of  all,  which  extends  along  the 
coast  of  North  America  to  the  icy  regions,  where  the  polar  currents 
accumulate  these  debris  with  those  of  other  parts  of  the  world. 

We  cannot  doubt,  on  reflecting  on  the  quantity  of  debris  borne  by  the 
waters,  that  Jakes  which  receive  rivers  are  filled  up,  little  by  little,  by  the 
matters  daily  brought  into  them ;  this  is  evident,  in  some  places,  where 
marshes  and  considerable  alluvions  are  thus  formed.  The  same  must  be  true 
of  the  bottom  of  the  sea,  where  all  waters  finally  come ;  it  is  easy  to  con- 
ceive there  must  be  daily  formed  considerable  dq>osits  of  all  the  substances 
which  are  carried  there,  as  well  as  of  those  washed  away  by  the  waves,  and 
of  all  the  remains  of  animals  which  perish  in  this  vast  abyss. 

30.  Deposits  of  substances  held  in  solution. — Waters  degrade 

28.  Are  all  the  materials,  transported  by  waters,  of  a  mineral  origin  ?  How 
are  the  rafts  in  the  Mississippi  formed  ? 

29.  What  effects  are  due  to  currents  of  the  sea  ? 


136     DEPOSITS  OF  SUBSTANCES  HELD  IN  SOLUTION. 

and  carry  away  different  substances  ;  some  they  also  dissolve,  and 
afterwards  deposit  them,  by  evaporation,  in  form  of  solid  sediments, 
which  are  sometimes  more  or  Jess  crystalline.  To  the  infiltration 
of  these  waters,  for  example,  is  due  all  kinds  of  stala'ctites  (from 
the  Greek  stalasso,  I  drop),  which  form  in  various  subterraneous 
cavities,  and  especially  large  in  caverns  found  in  calcareous  coun- 
tries. Certain  waters  are  rich  in  dissolved  materials,  and  suffi- 
ciently abundant  to  give  rise  to  extensive  deposits  on  the  surface 
of  the  earth.  Those  particularly,  which,  by  carbonic  acid,  hold 
a  great  quantity  of  carbonate  of  lime  in  solution,  and  which,  from 
abundant  or  numerous  springs,  give  origin  to  rivulets  and  even 
lakes,  at  the  bottom  of  which  is  daily  formed  what  is  called  traver- 
tin or  calcareous  tufa.  These  waters  are  met  almost  everywhere, 
in  calcareous  regions.  Scattered  over  a  flat  country,  or  on  the  slope 
of  a  valley,  these  waters  incrust  the  plants  growing  there,  and, 
from  these  agglomerated  and  superposed  incrustations  are  formed 
considerable  rocks,  the  mass  of  which  is  consolidated  by  waters 
which  percolate  the  interstices  they  meet,  and  render  the  whole 
solid  and  uniform.  When  these  waters  flow  over  slopes  free  from 
vegetation,  they  deposit  thin  and  successive  layers,  following  the 
undulations,  the  whole  forming  compact  masses  which  daily  grow 
in  thickness.  In  lakes  into  which  waters  of  this  kind  flow,  hori- 
zontal beds  of  solid  calcareous  matter  are  formed,  which  are  often 
filled  with  fluviatile,  and  even  terrestrial  shells,  daily  brought 
into  it. 

31.  Sands  washed  up  by  waves,  either  in  fresh-water  lakes  or 
seas,  are  daily  consolidated  by  waters  more  or  less  charged  with 
carbonate  of  lime.     Examples  of  this  kind  are  seen  in  the  sands 
of  lake  Superior,  in  those  of  the  gulf  of  Messina,  at  several  points 
on  the  coasts  of  England,  of  the  West-India  islands,  chiefly  at 
Guadaloupe,  New  Holland,  &c.      These  arena'ceous  substances 
often  become  sufficiently  solid  for  building  purposes. 

32.  Sili'cious  deposits. — A  great  many  mineral  waters,  particu- 
larly those  which  are  warm  or  hot,  contain,  besides  carbonate  of 
lime,  a  certain  quantity  of  silex  (from  the  Greek  chalis,  a  pebble) ; 
on  this  account  many  calcareous  tu'fas  are  more  or  less  silicious. 
But  there  are  springs  in  which  the  silex  is  sufficiently  abundant  to 
form  considerable  deposits  of  hydrated  sili'cious  deposits,  some- 
limes  nearly  pure,  and  sometimes  mingled  with  other  substances. 
The  tu'fas  of  the  geyser  in  Iceland  are  deposited  for  nearly  a 
quarter  of  a  league  round  the  spring,  three-quarters  of  a  yard  thick. 
One  of  these  geysers  (a  word  which  according  to  some  means 
spouting,  and  furious,  according  to  others)  spout?  up  every  half 

30.  How  do  waters  form  deposits  from  matter  held  in  solution  1     What 
are  stala'ctites? 

31.  By  what  means  are  sands  consolidated? 

32.  How  are  sili'cious  deposits  formed  ?     What  is  a  geyser  ? 


STRUCTURE  OF  SEDIMENTARY  DEPOSITS.  137 

hour  a  column  of  boiling  water,  eighteen  feet  in  diameter  and  one 
hundred  and  fifty  feet  high.  Analogous  springs  of  hot  water  exist 
in  the  Rocky  mountains,  and  in  India,  as  well  as  in  Saint  Michael's 
(Azores),  where  the  sili'cious  deposits  are  found  in  thin  beds,  alter- 
nating with  argilla'ceous  substances  which  the  same  waters  bring 
from  the  interior  of  the  earth.  Organic  remains,  particularly  vege- 
table, are  found  in  all,  some  of  which  have  passed  into  the  sili'cious 
slate,  while  others  have  disappeared,  leaving  only  their  impressions 
behind. 

33.  Structure  of  sedimentary  deposits. — Effects  of  land-falls. — 
If  we  examine  deposits  of  de'tritus,  formed  at  the  foot  of  mountains 
by  the  daily  destruction  of  its  rocks,  it  will  be  seen  their  slopes 
are  very  variable,  the  greatest  not  exceeding  an  angle  of  forty-five 
degrees,  and  the  least  being  seldom  less  than  twenty  degrees ;  the 
variations  between  these  limits  are  found  to  be  in  relation  to  the 
size,  the  form  of  the  fragments,  and  circumstances  of  the  fall, 
rather  than  to  the  nature  of  the  substances  themselves.     Hence  it 
is,  if,  at  different  successive  fallings,  there  are  variations  in  the  form 
of  the  fragments  and  in  the  circumstances  of  the  fall,  there  will  be 
an  accumulation  of  deposits,  the  slopes  of  which  will  be  succes- 
sively less,  and  which,  in  ravines  ^ 

excavated   by  water,  will   have 
nearly  the   arrrangement  repre-  ^ 
sented,  a,  b,  c,  d,  e,  (fig.  210),  | 
where  each  additional  deposit  is  II 
thicker  at  its  base  than  at  the  ° 
upper  part.      It  is  evident  the 
same   thing   may  take   place  in 
stagnant  waters ;   whence  it  fol- 
lows that  from  the  fall  of  a  river      _.     ~ir 
into  a  lake  with  steep  banks,  a     **  216.- 7W«.  from  fatting. 

very  considerable  ta'lus  may  be  formed,  and  from  different  acces- 
sions or  growths,  which  bring  materials  of  different  form  and  size, 
deposits  similar  to  those  just  mentioned  may  be  produced. 

34.  Effects  of  transport. — If  in  some  places,  even  under  water, 
beds  may  be  deposited  at  an  inclination  of  from  twenty  to  forty-five 
degrees,  it  must  not  be  inferred  that  the  same  is  true  of  extensive 
deposits,  where  running  waters,  if  unimpeded,  may  force  the  debris 
in  every  direction.     Here  the  inclination  of  the  ta'lus  is  much  less  ; 
they  never  attain  even  the  minimum  angle  of  slopes  farmed  of 
fallen  matter,  and  never  reach  even  ten  or  twelve  degrees,  only  in 
exceptional  cases  of  very  rapid  torrents,  or  rather  of  true  cascades, 
at  the  place  where  they  fall  into  a  transverse  valley,  and  where 
there  is  as  much  matter  tumbled  down  as  transported.     The  beds 
of  the  most  rapid  rivers  are  much  less  inclined,  and  the  successive 


33.  What  is  the  structure  of  deposits  from  land-falls  ? 

34.  Is  the  angle  or  slope  of  a  ta'lus  always  the  same  ? 

12* 


138 


EFFECTS  OF  TRANSPORT. 


deposits  are  for  the  most  part  nearly  horizontal.  Gravel  and  sand 
which  the  waves  wash  upon  coasts,  are  also  deposited  at  very 
small  angles,  and  slopes  of  ten  degrees  are  exceptions,  even  in 
localities  exposed  to  the  strongest  billows ;  most  frequently  they 
are  much  less,  and  nearly  horizontal. 

35.  It  frequently  happens,  during  the  drift  or  transportation  of 
matters  by  currents,  and  by  freshets  in  rivers,  when  the  bottom  is 
disturbed,  that  effects  analogous  to  those  of  sea-winds  on  dunes 
are  produced.  Ridges  are  formed  across  the  current ;  various  mat- 
ters, pushed  over  these  initial  hillocks,  accumulate  behind  them, 
forming  a  ta'lus  of  successive  fallings,  which  impart  the  structure 
represented  in  fig.  217.  If  the  river  change  its  course,  the  undu- 
lated surface  of  the  first  deposit  is  soon  levelled,  and  quiet  deposits 
are  formed  above  (Jig-  218),  from  which  the  preceding  may  be 
distinguished  by  the  particular  structure  attributable  to  the  circum- 
stances of  its  formation. 


Fig.  217.  Fig.  218. 

Structure  produced  by  the  transportation  of  materials. 

These  effects,  resulting  from  a  mixture  of  rapid  and  tranquil 
deposits  (that  is,  deposits  formed  from  rapid  currents  and  tranquil 
waters),  are  very  clearly  seen  in  alluvions  on  river  banks,  and  par- 
ticularly in  deltas,  which  terminate  their  course  when  the  waters 
have  excavated  some  ravine  near  by.  We  then  perceive  that  the 
mass  of  the  deposit  is  formed  of  horizontal  layers,  having  a  surface 
more  or  less  undulated  (Jig.  219),  which  are  distinguished  from 


Fig.  219. — Structure  of  alluvions  in  rivers. 

each  other  by  the  size  of  the  component  parts,  by  the  colour,  by 
the  structure  produced  by  rapid  accumulation,  either  by  pushing 
forward  the  matters  in  the  direction  of  the  ordinary  current,  as  in 
the  deposits  a  and  £,  or  in  a  different  direction,  as  in  the  deposit  c, 
which  indicate  counter-currents  formed  at  one  time  or  another. 
Often  there  are  particular  masses,  d,  formed  here  and  there,  which 
ordinarily  consist  of  coarser  gravel,  or  of  different  organic  debris. 

35.  What  effects  result  from  transportation  or  drift  ? 


EFFECTS  OF  OSCILLATORY  MOTION.  139 

36.  Effects  of  oscillatory  motion. — Great  masses  of  water,  sub- 
ject, like  the  sea,  to  undulalory  motion,  present  another  order  of 
facts ;  not  only  are  suspended  substances  deposited  there  in  hori- 
zontal beds,  as  a  more  weighty  fluid  would  do,  but  the  slightest 
agitation  does  not  permit  any  material  particle  to  be  solidly  fixed 
on  planes  of  the  least  inclination,  but  tends,  on  the  contrary,  to  de- 
stroy all  inequalities  of  the  bottom.  It  is  impossible  to  ascertain 
positively  these  effects  at  the  bottom  of  the  sea ;  but  the  immense 
number  of  soundings,  taken  in  all  parts  of  the  ocean  by  navigators, 
show  that  all  moving  bottoms  have  very  slight  inclination ;  that 
slopes,  at  an  angle  of  half  a  degree,  are  rare,  and  that  all  above  this 
are  exceptions :  hence  it  follows,  that  in  great  masses  of  water, 
beds  formed  by  successive  deposits  must  be  entirely  horizontal. 
This  fact  is  most  clearly  exhibited  in  certain  lakes,  which  have 
been  entirely  or  in  part  dried  up,  where  alternations  of  beds,  of 
every  kind,  are  seen  to  be  perfectly  horizontal ;  lakes  Superior  and 
Huron  furnish  examples  of  this  kind. 

3^.  This  disposition  of  various  matters  deposited  from  water, 
bed  by  bed,  at  the  bottom  of  rivers,  lakes,  marshes,  is  termed  strati- 
fication ;  the  deposits  themselves  are  said  to  be  stratified.  This 
circumstance  eminently  distinguishes  deposits  formed  by  water, 
from  those  produced  by  igneous  fusion,  which  are  most  frequently 
massive,  or  irregularly  divided. 

38.  Nature  of  deposits — organic  remains. — Beds  of  alluvium 
are  formed  of  rolled  flints,  gravel,  and  sand,  as  well  as  of  various 
kinds  of  mud,  analogous  to  matter  called  clay  or  argil.  They 
are  more  or  less  consolidated,  as  much  by  their  own  weight, 
as  by  waters  charged  with  carbonate  of  lime,  or  various  matters 
which  may  penetrate  them.  In  lakes,  we  see  calca'reous  and  ar- 
gilla'ceous  marls,  which  have  the  property  of  hardening  in  the  air, 
as  has  been  observed  in  certain  half-dried  lakes  in  Scotland,  in 
modern  building-stone  found  in  Hungary,  and  in  lakes  Superior 
and  Huron.  Similar  formations  doubtlessly  occur  in  the  sea,  as 
waters  are  sufficiently  calci'ferous  to  consolidate  the  sands  thrown 
on  its  coasts  ;  and  the  nature  of  upheaved  deposits,  in  many  places, 
leave  no  uncertainty  in  this  respect. 

These  deposits  are  frequently  filled-  with  remains  of  all  the  organized 
creatures  now  living1  on  the  surface  of  the  globe.  In  river  alluvium  we  find 
remains  of  fluviatile  shells  that  still  live  in  the  same  localities,  or  land  shells, 
such  as  various  snails,  brought  thither  by  rivulets ;  there  are  branches  and 
trunks  of  trees,  masses  of  plants,  more  or  less  changed,  sometimes  partly 
bitumenized,  bones  of  terrestrial  or  aquatic  animals,  rarely  human  bones, 
but  frequently  the  remains  of  art,  such  as  fragments  of  brick  and  pottery, 
&c. 

36.  What  is  the  position  of  strata  formed  under  the  influence  of  undula- 
tory  motion  of  water? 

37.  What  is  meant  by  stratification  ? 

38.  Of  what  do  beds  of  alluvium  consist  ? 


140  CORAL  REEFS. 


Alluvions  formed  by  the  sea  are  very  similar ;  they  contain  marine  debris 
of  every  kind,  sometimes  alone  and  sometimes  mingled  with  fluviatile  and 
terrestrial  debris,  brought  into  it  by  rivers.  Debris  of*  human  industry,  an. 
chors,  boats,  &c.,  are  frequent,  and  even  man's  remains  exist ;  not  only  in 
cemeteries  of  villages  that  have  been  overwhelmed  by  sands,  but  also  among 
the  debris  cast  up  by  the  sea,  as  at  Guadaloupe,  where  human  bones  are 
found  in  a  sand  consolidated  by  a  calca'reous  tu'fa,  and  mingled  with  debris 
of  human  art.  In  deltas  formed  partly  of  fresh  water  and  partly  by  the  sea, 
we  find  alternate  layers,  the  one  filled  with  marine  debris,  and  the  others  by 
those  of  fresh  water;  but,  under  other  circumstances,  all  these  remains  are 
found  indiscriminately  mingled. 

Argilla'ceous,  marly,  or  calca'reous  deposits,  in  lakes,  contain  the  remains 
of  fluviatile  and  terrestrial  mollusks,  similar  to  those  now  existing  in  the 
same  regions.  Remains  of  fishes  and  mammals  are  also  occasionally  found. 
There  is  no  doubt  deposits  formed  in  the  sea  also  contain  remains  of 
the  numerous  animals  that  daily  perish.  We  learn  from  soundings  that  the 
bottom  of  the  sea,  in  many  places,  is  covered  by  shells,  broken  or  entire, 
fragments  of  madrepore,  echinidae,  &c.,  sometimes  mingled  with  sand, 
sometimes  by  themselves,  constituting  considerable  banks  in  progress  of 
formation  and  consolidation. 

39.  Coral  reefs. — Formations  of  stony  polypa'ria,  agglomerated 
with  each  other,  often  of  great  extent,  are  thus  named ;  in  inter- 
tropical  regions  they  constitute  a  great  number  of  islands,  on  a  level 
with  the  sea,  or  submarine  banks,  the  mass  of  which  rises  more 
and  more.  It  is  scarcely  twenty  years  since  it  was  supposed  that 
the  little  animals  \vhich  form  these  deposits,  by  a  calcareous  exu- 
dation, had  the  faculty  of  living  at  great  depths  in  the  ocean  ;  it 
was  thought  they  began  their  dwelling,  and  gradually  augmented 
the  mass,  until  it  formed  immense  mountains,  the  summits  of 
which  constituted  the  reefs,  and  that  they  gave  origin  to  most  of 
the  large  islands  formed  in  those  regions.  These  microscopic 
creatures,  it  was  said,  tended  thus  to  fill  up  the  ocean,  and  were 
preparing  prodigious  changes  on  the  surface  of  the  globe.  But  all 
this  exaggeration  has  disappeared,  the  observations  of  MM.  Q,uoi 
and  Gaimard  having  shown,  that  the  species  which  contribute  most 
to  the  formation  of  reefs,^uch  as  caryophy'llisc  (Jig.  220),  mean- 
dri'nse  (Jig.  221),  and  particularly  the  as'lrcsc  (fig.  222),  which 
sometimes  cover  immense  spaces,  and  various  madrepores  (Jig- 
223),  cannot  exist  except  at  moderate  depths,  and  ten  or  twelve 
yards  below  the  surface  no  trace  of  them  is  to  be  found.  It  is, 
then,  on  pre-existing  rocks,  already  elevated  under  wrater,  often 
very  steep  on  the  sides,  as  soundings  show,  that  these  animals 
begin  to  build  ;  and  from  this  they  afterwards  accumulate  their 
solid  product  to  the  level  of  the  sea,  where  their  last  generations 
perish.  They  cannot,  then,  fill  up  the  ocean  ;  but  the  incrusta- 
tions they  form  are  not  the  less  important,  since  they  are  sometimes 
ten  or  twelve  yards  thick,  extending  over  immense  spaces,  and 
these  are  found  in  a  great  many  places  in  all  seas  comprehended 

39.  In  what  parts  of  the  world  do  we  find  coral  reefs  ?  How  are  they 
formed  ?  At  what  depths  do  polypa'ria  live  ? 


CORAL  REEFS. 


Ill 


Fig.  220. — Caryophy'llia  fastigiata. 


Fig.  223. — Madrcpo'ra  murica'la. 


Fig.  221. — Meandri'na  labyri'nthica. 


Fig.  222. — Astrea  viridis. 


between  the  tropics.  They  crown  most  submarine  mountains,  and 
cover  thousands  of  square  leagues,  distributed  among  thousands  of 
islands  and  reefs. 

40.  These  sa'xigenous  polypa'ria,  attached  to  every  kind  of 
rock,  surround  most  large  islands  with  their  products,  forming 
around  them  a  kind  of  rampart,  separated  frequently  by  deep 
water.  In  other  instances  they  form  islets,  detached  or  grouped  in 
different  ways,  and  they  are,  when  there  are  breakers,  the  more 
dangerous,  because  they  are  not  seen  before  being  cast  upon  them, 
and  because  the  depth  of  water  is  so  great  as  not  to  afford  anchorage. 
It  is  these  deposits  which  render  navigation  so  difficult  in  certain 
parts  of  the  South  Sea,  and  cause  so  many  deplorable  losses  by 
shipwreck.  Some  of  the  forms  assumed  by  these  deposits  at  the 
surface  of  the  sea  are  particularly  remarkable,  and  are  not  yet 
entirely  explained  ;  sometimes  these  reefs  are  completely  annular 

40.  What  is  the  form  of  coral  islands  ? 


142 


CORAL  ISLANDS. 


Fig.  224. — Coral  island  in  the  Pacific  Ocean. 

(fig.  224),  with  a  lake  in  the  centre,  enclosed  on  all  sides ;  some- 
times they  form  broken  circles,  having-  one  or  more  openings 
through  which  the  centre  may  be  reached  ;  again,  they  are  in 
groups  of  islands,  arranged  in  a  circle,  and  frequently  there  are 
several  in  a  series.  In  these  internal  seas  the  water  is  often  very 
deep — but  sometimes  very  shallow,  and  an  immense  number  of 
polypa'ria  are  developed,  which  sooner  or  later  fill  up  the  space. 
It  appears  evident  that  these  circular  reefs  are  the  edges  of  different 
upheaved  craters,  upon  which  the  polyps  have  established  them- 
selves ;  this  is  inferred  from  the  volcanic  nature  of  most  islands  in 
the  Pacific,  and  from  the  manner  in  \vhich  submarine  eruptions 
sometimes  take  place.  Nevertheless,  this  explanation  is  not  re- 
ceived as  satisfactory  in  respect  to  many  reefs  of  the  kind,  and 
particularly  those  which  constitute  -the  Maldives  and  Lakadives, 
groups  in  the  Indian  Ocean.  The  great  number  of  circular  groups 
found  in  certain  localities,  and  the  immense  expanse  which  we 
must  suppose  craters  of  elevation  to  have  in  other  places,  are  facts 
urged  in  objection  to  the  explanation. 

Around  cor.il  reefs,  as  well  as  in  the  lakes  they  enclose,  soft  and  white 
mud  of  a  calcareous  nature,  analogous  to  chalk,  has  been  observed,  which 
has  sometimes  been  referred  to  the  disintegration  of  madrepores,  and  some- 
times to  dejections  of  worm's  which  pierce  the  polypa'ria,  or  to  those  of 
fishes  which  feed  on  them.  In  many  places  in  the  South  Seas  this  mud 
seems  to  constitute  considerable  deposits. 

41.  When  a  reef  has  reached  the  level  of  the  water,  the  sea 
often  covers  it  with  debris  of  every  kind,  on  which  vegetation  is 
afterwards  developed.  Most  low  islands  in  the  Pacific  have  been 
produced  in  this  way,  all  of  which  rest  on  masses  of  polypa'ria. 
A  great  many  other* islands  have  sprung  up  on  their  coasts  in  the 

me  way ;  and  there  are  many  which  will  sooner  or  later  grow 


same 


41.  How  are  coral  islands  formed  ? 


PEAT,  OR  TURF  BOG.  143 

up  in  the  same  manner,  for  now,  at  low  tide,  we  may  walk  over 
reefs  extending  half  a  league  from  the  shore.  But  one  very  im- 
portant circumstance  is,  that  in  many  places  we  find  precisely  simi- 
lar deposits,  composed  of  the  same  species  of  madrepores,  in  the 
interior  of  land  at  an  elevation  of  from  200  to  300  ya-rds ;  this  is 
seen  at  Timor,  where  the  deposits  are  ten  or  twelve  yards  thick ; 
at  New  Holland,  Van  Diemen's  Land,  at  the  Marian  Islands, 
Sandwich  Islands,  &c.,  where  they  rest  on  argilla'ceous  schist, 
sandstone,  limestone,  volcanic  products,  &c. ;.  in  the  Isle  of  France 
a  similar  bank,  four  yards  thick,  is  found  placed  between  two  cur- 
rents of  lava.  The  existence  of  these  deposits  in  such  situations 
evidently  indicates  that  all  these  islands  have  been  upheaved  from 
the  bosom  of  the  waters,  and  often  at  several  different  periods,  for 
we  often  find  banks  of  coral  at  different  levels. 

42.  Peat,  or  Turf  Bog. — There  are  daily  formed,  in  different 
excavations  of  Jihe  surface,  in  valleys  of  gentle  slope,  in  low  and 
marshy  situations,  deposits  of  vegetable  matter,  the  decomposition 
of  which  furnishes  a  combustible  called  turf  or  peat,  and  the 
mass  bears  the  name  of  peat-bog.     These  deposits  are  formed 
only  under  particular  circumstances  :  they  are  seen  only  in  places 
where  stagnant  waters  constantly  exist,  and  only  in  shallow  depths ; 
the  presence  of  light  is  necessary  to  secure  vegetation,  to  which 
peat  chiefly  owes  its  origin. 

The  production  of  peat,  to  which  all  aquatic  plants  contribute,  is  princi- 
pally owing,  however,  to  those  which  are  always  submerged,  and  which 
multiply  rapidly;  their  debris  form  the  principal  paste  that  envelopes  all  the 
others,  and  probably  contributes  to  their  decomposition.  A  number  of  ter- 
restrial plants  also,  brought  to  these  bogs  by  brooks,  contribute  to  the  forma- 
tion. Frequently  large  trees  are  found  buried  in  the  mass,  particularly  in 
the  lower  parts,  where  they  accumulate  on  sands  and  clays  which  form  the 
bottom.  Often  they  are  seen  broken  and  fallen  near  the  root,  which  is  found 
attached  to  the  bottom  of  the  bog.  In  some  instances  these  debris  are  very 
numerous,  and  seem  to  indicate  that  entire  forests  must  have  been  buried 
on  the  spot  where  they  grew,  before  the  formation  of  peat.  The  plants  found 
in  these  situations  all  belong  to  existing  species  ;  they  are  resinous  trees, 
oaks,  birch,  &c.  Remains  of  mammals  are  often  found  in  peat.-bogs,  such  as 
the  bones  of  oxen,  the  horns  of  deer,  tusks  of  wild-boars,  &c. 

43.  Peat-bogs  rest  on  every  variety  of  soil,  sometimes  even  on 
crystalline  rocks ;  most  generally,  however,  they  overlie  deposits 
of  sand  or  clay,  and  sometimes  the  rolled  flints  of  the  country. 
There  are  places  where  accumulated  debris  of  plants  form  but  a 
single  mass,  of  greater  or  less  thickness",  more  compact  and  blacker 
at  the  lower  part  than  in  subsequently  formed  parts  of  it ;  there 
are  other  places  where  the  different  beds  are  separated  by  sedi- 
mentary deposits  of  alluvium.     These  are  formed  of  sands,  clays, 
calca'reous  or  argilla'ceous  marls,  often  containing  fresh-water  shells 
in  great  quantity.     Sometimes  the  surface  of  the  deposit  remains 

42.  What  are  peat-bogs  ?     Of  what  do  they  consist? 

43.  On  what  do  peat-bogs  rest  ? 


144  CONSEQUENCES  OF  CENTRAL  HEAT. 

covered  by  water,  and  at  others  it  is  covered  by  a  luxuriant  vege- 
tation. 

44.  Peat-bogs  are  numerous  in  different  parts  of  the  world  ; 
they  occupy  basins  or  depressions  in  the  soil  at  different  elevations, 
even  in  the  Alps.  One-tenth  of  the  whole  surface  of  Ireland  is 
said  to  be  covered  by  peat-bog.  In  the  Great  Dismal  Swamp  of 
Virginia  and  North  Carolina,  there  is  a  deposit  of  peat  from  ten  to 
fifteen  feet  in  thickness. 


LESSON  VIII. 

EXPLANATION  OF  VARIOUS  PHENOMENA. — Consequences  of  Central 
Heat  —  First  effect  of  cooling  —  Warm  Springs  —  Deposits 
referable  to  Sediment — Fresh-water  Deposits — Fossils  of  Ma- 
rine Deposits — Fossils  of  Carbona'ceous  Deposits. 

EFFECTS  ATTRIBUTABLE  TO  UPHEAVAL  AND  SUBSIDENCE. —  Shell 
Deposits  and  raised  Beaches — Submarine  Forests — Tracks  of 
Quadrupeds  and  Birds — Dislocation  of  Strata — Faults — Cra- 
te1riform  arrangement  of  Strata — Valleys  of  Elevation — Up- 
heaval without  Dislocation — Distortion  of  Strata — Origin  of 
Valleys  —  Valleys  from  Dislocation,  from  Subsidence,  from 
Folding  or  Plaiting,  from  Erosion  or  Denudation — Origin 
of  Caverns. 

Having  established  the  fact  of  a  central  heat  capable  of  keeping-  every, 
thing  in  a  state  of  fusion,  at  a  short  distance  beneath  the  surface  we  inhabit; 
having  shown  the  actual  effects  of  earthquakes  and  of  volcanic  action  ; 
having  pointed  out  those  which  waters  produce,  both  by  denudation,  or  de- 
gradation, and  the  formation  of  new  deposits,  it  is  natural  to  attempt,  by 
reference  to  these  effects,  the  explanation  of  all  geological  phenomena  which 
have  occurred  on  the  surface  of  the  globe  from  the  first  moment  of  its  exist- 
encc.  The  causes  now  in  action  are  the  same  as  those  which  have  acted 
through  all  time;  but  doubtlessly  they  were  more  energetic  at  certain  epochs 
than  present  observation  shows. 

'  1.  CONSEQUENCES  OF  CENTRAL  HEAT. — The  complete  fluidity 
of  the  globe  gave  rise  to  its  ellipsoidal  form :  the  heat  so  long  pre- 
served, and  still  existing  beneath  the  cooled  pellicle  or  crust,  has 
produced,  and  is  now  producing  a  great  number  of  phenomena. 
The  temperature  of  the  surface  is  nearly  stationary,  and  has  not 
varied  since  the  period  of  records,  and  will  not  probably  change. 
But  before  reaching  this  state,  which  probably  required  thousands 

44.  Where  are  peat-bogs  found  ? 

1 .  What  influence  is  central  heat  supposed  to  exercise  over  the  form  of 
the  globe  ?  Had  the  central  heat  any  influence  on  climate  ?  How  do  you 
account  for  the  fossils  of  tropical  plants  and  animals  being  found  in  northern 
regions  ? 


CONSEQUENCES  OF  CENTRAL  HEAT. 


145 


of  years,  the  surface  of  the  earth  must  have  passed  through  every 
degree  of  heat,  from  the  state  of  fusion  in  which  the  centre  still  is 
to  its  present  degree  of  cold  ;  consequently,  there  was  a  time  when 
the  temperature  of  the  earth  was  such  as  to  do  away  with  differences 
of  climate,  or  an  atmosphere  of  vapour,  which,  hy  overcoming  radia- 
tion, diminished  the  rigour  of  winter.  Then  vegetation,  and  life 
generally,  could  be  as  equally  maintained  in  all  latitudes  as  in  a 
hot-house.  From  this  it  follows,  that  plants  and  animals  now  found 
only  between^the  tropics  could  then  live  anywhere,  even  under  the 
poles,  which  were  not  then  encumbered  in  ice.  It  is  therefore  not 
astonishing  that  we  should  find  the  remains  of  these  various  creatures 
buried  nearly  on  the  spot  where  they  lived,  in  countries  which  are 
now  the  coldest  in  the  world,  and  in  which  it  would  be  impossible 
for  them  to  live  at  the  present  time. 

There  is  in  England,  on  the  island  of  Portland,  and  at  several  places  on 
the  continent,  intercalated  in  other  deposits,  a  bed  of  black  matter,  called 
dirt-bed,  and  small  argilla'ceous  beds,  in  which,  among  a  great  many  vege- 
table remains,  bedded  and  scattered,  are  various  plants  in  their  place  of 
growth  (fig.  225),  the  roots  "of  which  extend  into  the  fissures  of  the  calca- 
reous soil  beneath.  There- 
fore, there  must  have  been  a 
vegetable  soil,  on  which  all 
the  plants  now  buried  in  the 
earth  then  grew.  But  all 
the  species  found  in  this  bed 
belong  to  genera,  such 
cycas  and  zamia,  which 
now  live  only  in  the  tropics, 
and  the  remains  of  animals  FiS-  ^.—Portland  dirt-led. 

also  belonged  to  the  same  zone ;  consequently  the  mean  temperature  at  the 
time  of  this  formation  was  very  different  from  what  it  is  now  in  England. 

Most  of  the  coal  deposits  of  Europe  lead  to  a  similar  conclusion.  Entire 
trees  with  their  roots,  many  of  them  still  erect,  are  found,  as  in  the  mine  of 
Treuil,  near  St.  Etienne  (Jig.  226),  in  the  mines  of  Anzin  (North)  in  Eng- 
land, in  Scotland,  &.C.,  which  seem  to  indicate,  as  in  peat-bogs,  plants  that 
grew  very  near  the  places  where  they  are  now  found.  It  is  evident  from 
the  perfect  preservation  of  the  most  delicate  parts  of  plants,  the  manner  in 
which  the  leaves  are  extended  on  schists,  that  these  remains  could  not  have 
been  carried  far.  All  the  remains  of  plants  found  in  these  deposits  belong 
to  the  equisita'ceae,  lofty  ferns,  to  the  lycopodea'ceae,  &c.,  and  cannot  be 
compared  with  those  now  existing  in  the  tropics;  consequently,  the  climate 
of  Europe  must  have  been  then  very  different  from  what  it  is  at  present. 

We  find,  in  the  latitudes  of  Europe,  certain  beds  containing  the  remains 
of  intertropieal  plants,  but  we  also  find  above  them  considerable  deposits  in 
which  are  dicotyle'donous  plants  of  the  present  time.  The  formation  of  the 
Inst  deposits,  then,  must  have  taken  place  long  after  the  first;  and  it  is  pro- 
bable that  between  the  epochs,  a  period  of  time  elapsed,  sufficient  for  cooling 
the  surface  of  our  planet. 

Madrepores  of  reefs,  which  now  do  not  exist  beyond  the  tropics,  then  evi- 
dently extended  to  the  polar  circle.  In  fact,  the  limestones  of  different 
periods  contain  a  great  number,  and  frequently  show  that  reefs  existed  corn- 
parable  to  those  of  our  days.  Facts  show  that  the  limits  of  these  banks  of 
zo'ophytes  have  retrograded,  from  the  period  of  the  deposit  of  the  oldest 
13 


146 


CONSEQUENCES  OF  CENTRAL  HEAT. 


Fig,  226. —  Vertical  stems  in  the  mine  of  Treuil,  St.  Elie.nnc. 

limestones  to  that  of  the  chalk,  after  which  they  suddenly  retired  to  their 
present  limits  ;  in  other  words,  the  climate  of  Europe  has  grown  successively 
colder. 

First  effect  of  cooling. — The  idea  of  complete  fusion,  and  of  cooling,  which 
the  observation  of  the  phenomena  forcibly  leads  us  to  admit,  also  leads  us  to 
conceive  what  must  have  taken  place  on  the  first  consolidation  of  the  globe's 
surface.  The  first  solid  pellicle  formed  underwent,  from  cooling,  more  or 
less  contraction,  and  on  this  account  must  have  broken  in  all  directions, 
from  the  action  of  the  melted  matter  it  covered,  swimming  in  pieces  on  its 
surface,  and  uniting  anew  more  or  less  irregularly,  to  be  again  broken.  But 
assuming  greater  consistence,  and  pressing  more  and  more  on  the  liquid 
part,  this  must  have  gushed  up  through  the  rents,  then  more  rare,  and  formed 
above  the  crust  projecting  ridges,  of  more  or  less  extent,  which  increased  in 
height  in  proportion  as  the  resistance  of  the.  crust  became  greater,  and 
caused  stronger  and  stronger  reaction.  Hence  the  first  rugosities,  the  first 
ridges  formed  on  the  surface  of  the  globe,  which  possibly  afforded  the  first 
hold  for  the  action  of  water,  the  precipitation  of  which  took  place,  without 
doubt,  long  before  the  temperature  of  the  teirostrial  crust  had  descended  to 
212°  of  Fahrenheit's  thermometer,  in  consequence  of  the  pressure  exerted 
by  the  vapour  then  diffused  in  the  air.  From  that  moment  waves  produced 
debris,  and  arena'ceous  matters,  and  sediments  began  to  form.  Probably 
the  water,  at  a  high  temperature,  charged  with  the  principles  disengaged 
from  the  solidified  masses,  like  lava  of  the  present  time,  attacked  the  stony 
matters,  disintegrated  and  dissolved  them,  and  subsequently  formed  chemical 
deposits,  or  consolidated  the  debris.  In  fact,  we  find  deposit?  formed  of 
fragments,  of  rolled  flints  and  of  sands,  in  the  most  ancient  layers  yet  exa- 
mined, and  before  meeting  with  organic  remains. 

All  the  solid  layers  formed  beneath  the  first  pellicle,  like  it,  being  sub- 
jetted  to  the  law"  of  contraction  from  cooling,  must  have  been  filled  with 
cracks  in  all  directions  ;  therefore  the  whole  terrestrial  crust,  thus  formed, 
could  not  have  been  as  solid  as  might  be  at  first  imagined :  it  could  not 


WARM  SPRINGS.  147 


resist,  so  successfully  as  might  be  thought,  the  internal  actions,  which,  meet- 
ing  no  obstacle  in  the  sedimentary  deposits  subsequently  formed,  must  have 
dislocated  them  in  all  ways.  In  fact,  there  is  no  deposit  on  the  surface  of 
the  globe,  either  sedimentary  or  crystalline,  which  is  not  found  to  be  cracked 
in  all  directions  ;  even  on  the  upper  surface,  most  rocks  are  broken  in  small 
fragments,  to  a  considerable  depth. 

While  the  crust  of  the  earth  was  gradually  cooling,  things  must  have 
passed  nearly  as  we  have  stated ;  but,  after  the  temperature  hud  become 
stationary,  as  it  is  now,  it  could  not'  have  been  the  same  :  the  superficial 
pellicle  docs  not  contract,  because  it  does  not  grow  sensibly  cooler.  Never- 
theless,  the  interior  mass  is  still  cooling  more  and  more,  although  with  ex- 
treme slowness*,  and  consequently  diminishing  in  volume  ;  now,  the  fluid 
part  tending  to  drag  with  it  that  which  covers  it,  and  which  becomes  suc- 
cessively too  large,  this  must  contract  on  itself,  and  ridge  the  surface  by  dis- 
locations through  its  whole  thickness.  This  may  take  place  tranquilly,  for 
some  time ;  but,  at  certain  moments,  the  effect  cannot  fail  to  take  place 
quickly,  and  hence  the  sudden  catastrophes  experienced  on  the  earth's  sur- 
face. 

All  observations,  in  accordance  with  geometrical  considerations,  show 
that  these  ridges  and  these  dislocations  arc  formed  according  to  the  great 
circle  of  the  sphere,  and  extend  over  the  half  of  its  circumference. 

2.  Warm  springs. — The  different  degrees  of  temperature  of 
warm  springs  are  referable  to  the  central  heat,  which  is  communi- 
cated through  fissures  of  greater  or  less  profundity.  The  waters 
come  to  the  surface  with  the  temperature  of  the  point  whence 
they  started,  and,  it  is  known,  that  at  the  depth  of  about  3280 
yards,  they  boil.  Now  it  may  be  readily  conceived  how,  during 
earthquakes,  new  hot  springs  may  appear  in  a  country,  and  how 
those  that  existed  there  may  be  lost ;  in  the  first  instance,  all  that  is 
required  is  a  fissure,  to  establish  a  communication  between  the 
surface  and  a  proper  depth  ;  and,  for  the  second,  that  the  existing 
communication  should  be  interrupted. 

We  may  easily  conceive,  also,  that  before  the  earth  had  reached  its  pre- 
sent degree  of  cooling,  hot  springs  must  have  been  infinitely  more  numerous 
than  they  are  at  present.  When,  instead  of  one-thirtieth  of  a  degree,  centi- 
grade per  yard,  the  temperature  increased  one-third  of  a  degree,  that  is,  ten 
times  more  rapidly  than  at  present,  and  when  water  boiled  at  a  depth  of  325 
yards,  it  is  clear,  there  must  have  been  a  great  many  springs  at  a  tempera- 
ture of  212°  Fahrenheit,  or  of  boiling  water,  and  that  fumarolles,  now  rare, 
were  then  common.  Consequently,  the  condition  of  the  atmosphere  was  then 
very  different  from  what  it  is  now ;  thick  fogs  must  have  spread  over  the 
surface  of  the  earth,  in  the  absence  of  the  sun,  and  hence  radialion  towards 
the  celestial  space,  at  present  an  important  cause  of  refrigeration,  must  then 
have  been  nothing.  Winter  was  consequently  less  rigorous ;  and  this  ex- 
plains, too,  how  so  many  plants  and  animals,  which  cannot  now  exist  in 
northern  climates,  could  then  live  in  them  as  between  the  tropics,  and  pre- 
cisely as  southern  plants  now  live  on  northern  coasts  and  islands  which  are 
constantly  shrouded  in  thick  fogs.  The  whole  earth,  tempered  by  these 

*  According  to  Fourier,  a  decrease  of  internal  heat  of  not  more  than  one 
degree  in  thirty  yards,  would  require  30,000  years. 

2.  How  is  the  temperature  of  hot  springs  accounted  for  ?  At  what  depth 
do  spring  waters  boil  ? 


148  DEPOSITS  REFERABLE  TO  SEDIMENT. 

abundant  vapours,  could  then  support  the  same  organic  creatures  ;  here  we 
have  the  reason  why  mineral  beds,  of  a  determined  age,  differ  less  in  the 
organic  remains  they  contain,  wherever  found,  than  existing  creatures  of 
different  zones. 

DEPOSITS    REFERABLE    TO    SEDIMENT. 

3.  Rolled  flints,  sand,  and  mud,  are  formed  by  the  action  of 
running  water  and  of  waves  ;   and,  being  transported  by  these 
waters,  they  accumulate  in  lakes,*  in  seas,  at  the  mouths  of  rivers, 
and  on  coasts.     Whenever  we  find  these  kinds  of  matter  accumu- 
lated in  more  or  less  considerable  deposits  in  the  interior  of  coun- 
tries, we  have  a  right  to  conclude  that  there  existed  somewhere,  far 
or  near,  high  mountains,  from  which  these  matters  were  detached ; 
water-courses,   which  carried   them ;  undulating   waters,   which 
heaped  them  up  on  their  shores,  and  often  lakes  and  seas,  that 
received  them.     By  the  greater  or  less  abundance  and  size  of  the 
rolled  flints,  we  can  judge  of  the  mass  and  force  of  the  waters  that 
transported  them;  and  their  nature,  and  various  course  or  track, 
ought  to  lead  to  the  point  of  their  origin,  if  circumstances  have  not 
destroyed  the  traces  left  by  currents  in  their  course. 

As  in  the  present  day  we  see  deposits  of  shells  formed  in  lakes  and  seas, 
we  infer  that  the  numerous  beds  of  the  same  kind  we  find  at  all  heights, 
even  on  the  summits  of  the  loftiest  mountains,  were  necessarily  formed 
under  water  ;  the  nature  of  the  organic  remains  enables  us  to  determine 
whether  they  were  deposited  under  fresh  or  salt  water,  on  coasts  or  in  depths 
of  the  sea;  their  mixture,  their  alternation,  indicate  mouths  of  rivers,  alter- 
nations of  salt  and  fresh  water,  &c. 

4.  Deposits  from  fresh  water. — These  deposits  are  easily  re- 
cognised from  me  organic  remains  they  contain  being  comparable 
to  different  genera,  sometimes  even  to  different  species  of  animals 
now  living  in  our  lakes  and  rivers.    These  are  especially  remains, 
impressions,  or  moulds  of  shells,  like  those  of  the  genus  limne'a 
(Jig-  227),  planor'bis  (Jig.  228),  paludi'na  (fig.  229),  mela'nia 
\fig.  230),  and  of  land  shells  of  the  genus  helix.     These  are  all 


Fig.  227.— Limne'a  Fig.  228.-  Piano' rbis   Fig.  229.— Paludi'na  Fig.  230.— Mela'- 

longisca'ta.  euom'phalus.  lenta.  niainqnina'ta. 

3.  How  are  rolled  flints  formed  ?  What  does  the  presence  of  a  deposit 
of  rolled  flints  in  a  country  indicate  ?  What  is  inferred  from  their  size  and 
quantity  ? 


MARINE  DEPOSITS. 


149 


univalve,  unilocular  shells.  The  bivalve  shells  of  fresh-water  de- 
posits, more  rare  than  the  preceding,  are  like  mussels — u'nio  (fig. 
231),  anodo'nta  (Jig-  232),  cy'clas  (Jig.  233),  and  cyre'na  (Jig. 
234).  The  entire  absence  of  every  species  of  polypa'ria  (figs. 


Fig.  231  —  U'nio    Fig.  232.—  Anodo'nta    Fig.  233.— Cy'clas 
littora' Us.  cordieri.  obo'vata. 


Fig.  234.— Cyre'na 
trigo'nula. 


235,  236,  237—239),  and  echini'deae  (figs.  238—240,  241),  is  an 

important  characteristic  of  fresh-water  deposits,  which  are  very 
common  in  different  parts  of  the"  world. 

5.  Marine  deposits. — These  are  distinguished  by  the  analogy 
of  the  organic  remains  they  contain  (figs.  235  to  250)  to  the' debris 


Fig.  M5.—Encri'nites 
monilifo'  rmis. 


Fig.  <236.—j9'piocri'nites 
rotu'ndus. 


Fig.  237. — Cy '  athocri  'nitea 
planus. 


4.  How  are  fresh-water  deposits  recognised  ?    Which  are  most  numerous, 
univalve  or  bivalve  shells,  in  fresh-water  deposits  ?     What  does  the  absence 
of  polypa'ria  indicate? 

5.  How  are  marine  deposits  distinguished  ?     What  fossils  are  character- 
istic  of  marine  deposits  ? 

13* 


150 


MARINE  DEPOSITS. 


of  different  animals  now  living  in  the  seas.  Polypa'ria.  more  or 
less  analogous  to  those  which  form  coral  reefs  (figs.  220  to  223 — 
p.  141),  are  highly  characteristic;  encri'nites  (jigs.  235  to  237), 


Fig:  238.—  Cida'ris  corona'ta.  Fig.  239 .—Different  joints  of  Encri'nites. 

or  the  remains  of  their  joints  (fig.  239) — the  echini'dese  (figs. 
338  to  241).  Not  one  of  these  organic  bodies  is  found  in  fresh 
water 


Fig.  240. — Qnanchytes  ovatus 
from  the  Parisian  chalk"). 


Fig.  '•Hl.—Spata'vgus  ambula'crum 
(from  the  chalk  of  the  Pyrenees}. 


Among  the  marine  univalves  there  are 
some  which  are  more  or  less  analogous  to 
those  of  fresh  water,  mentioned  (p.  148), 
although  they  are  thicker,  and  more  gene- 
rally covered  with  tubercles  (fig.  242). 
But,  setting  aside  those  on  which  at  first 
sight  there  might  be  some  doubt,  there  are 
many  others  which  are  sufficiently  charac- 
teristic :  these  are  shells  whose  aperture  is 
terminated  by  a  canal  of  greater  or  less 
length,  and  belong  either  to  the  genus  ceri'- 
thium  (fig.  243),  of  which  a  small  number 

Flg.M.-Turbo  costa'nus.     Q{  S*  J 


genera  mu'rex  (fig.  244),  volu'ta  (fig.  245),  &c.  ;  they  are  all 
marine,  and  abound  in  calcareous  deposits. 


MARINE  DEPOSITS. 


151 


Fig.  243.— Ceri'thium 
muta'bile. 


Fig.  <244.—Mu'rex 
alveola' tus. 


athle' ta. 


Marine  bivalve  shells  generally  differ  very  much  from  those 
found  in  fresh  water ;  some  resemble  oysters,  and  others  are  almost 
entirely  like  them ;  a  great  many  are  furnished  with  ribs,  or  striae, 
or  rugosities  (figs.  24(5,  247),  and  possess,  in  a  word,  many  cha- 
racteristics entirely  different  from  those  found  in  the  genera  we 
have  just  mentioned. 


Fig  %46.—C!iama 
folia' cea. 


Fig.  247,—  re'nerica'rdia       Mff.<i48.—Jfau'tilus 

imbrica'ta.  trunca'tus  (front  the  Lias). 


Chambered  shells  are  found  only  in  seas,  such  as  the  nautilus 
(.fig-  248)»  more  or  less  like  numerous  species  of  ammonites  (Jig. 
249),  no  analogue  of  which  is  now  living,  but  with  which  certain 
terrestrial  strata  are  filled. 

These  deposits  are  generally  formed  very  slowly,  by  the  accumulation  of 
shells  left  by  dead  mollusks  as  fast  as  they  perish,  and  not  by  sudden  catas- 
trophes, which  would  have  heaped  them  up  alive  in  greater  or  less  numbers. 


152  CARBONACEOUS  DEPOSITS. 


Fig.  250.— Sc'rpula,  on  the  inside  of  a 
Fig.  249.— jfrnwionz'tes  cate'na.  Ca'rdium  porulo'sum. 

This  is  proved  by  the  fact  that  frequently  on  the  inside  of  shells  we  find 
parasitic  animals,  that  attach  themselves  to  bodies  of  all  kinds  (Jig.  250), 
and  which  could  not  attach  themselves  here,  in  the  interior  of  the  shell,  if 
the  mollusk  had  not  been  previously  destroyed.  Often  the  very  shell  of 
the  parasite  is  covered  by  others,  showing  that  the  first  had  long  existed  in 
the  sea.  The  shells  of  bivalves  are  frequently  found  separated,  showing 
the  animal  must  have  died  before  they  were  buried.  And  there  are  shells 
which  are  pierced  by  Irthopha'gi,  as  well  as  the  flints  and  fragments  of 
limestone  which  accompany  them,  leading  to  the  same  conclusion.  There 
are  of  course  some  exceptions,  but  these  are  commonly  due  to  local  circum- 
stances. 

Generally,  these  shelly  deposits  are  on  the  spot  where  the  animals  lived. 
In  fact,  they  contain  a  great  number  of  uninjured  shells,  the  most  delicate 
appendages  of  which  are  in  a  state  of  perfect  preservation  ;  a  circumstance 
not  reconcilable  with  the  idea  of  transportation  by  currents,  which  would 
have  broken  the  whole  and  rounded  the  fragments.  Even  in  decomposition, 
the  finest  parts  have  left  their  impressions  on  the  substances  enveloping  them. 

By  means  of  the  debris  alluded  to,  we  may  always  recognize  marine 
deposits. 

6.  Carbona'ceous  deposits. — It  is  undeniable,  that  the  carbo- 
na'ceous  deposits  found  in  different  strata  of  the  earth,  were  pro- 
duced there  by  the  accumulation  of  the  remains  of  plants ;  this  is 
proved  by  the  numerous  and  clearly  characterized  remains  of 
stems  and  leaves  met  with,  either  in  the  combustible  mass  or  in 
the  earthy  matter  containing  it.  On  this  point  all  are  of  one  opinion; 
but  all  do  not  agree  as  to  the  manner  of  accumulation  of  these  re- 
mains. Some  geologists  suppose  that  all  carbona'ceous  deposits 
result  from  the  sinking  of  great  rafts  of  divers  plants,  transported 
by  great  rivers,  by  maritime  currents,  and  sunk  in  different  places; 
others  think,  on  the  contrary,  that  most  of  these  deposits  were 
formed,  in  place,  in  the  same  manner  as  peat-bogs,  in  depressions 
of  the  surface  to  which  rivulets  daily  brought  debris  from  the  sur- 
rounding vegetation. 

6.  From  what  are  carbona'ceous  deposits  derived?  How  are  carbona' 
ceous  deposits  formed  ? 


CARBONACEOUS  DEPOSITS.  153 

Opposed  to  the  idea  of  floating  rafts  is,  the  enormous  thickness  they  must 
have  attained,  to  have  produced  beds  of  coal  such  as  are  known,  between 
two  layers  of  arena'ceous  matter.  In  fact,  taking  into  consideration  the 
specific  weight  of  wood,  the  amount  of  carbon  it  contains  relatively  to  that 
of  carbona'eeous  deposits,  we  find  that  the  latter  can  only  be  twenty-two 
hundreds,  or  even  seven  hundreds  (according  to  the  kind  of  plants),  of 
the  primitive  volume  of  the  matters  which  gave  origin  to  them.  Besides, 
estimating  the  numerous  voids  left  by  the  irregular  interlacing  of  these 
debris  in  a  raft,  we  know  that  coal,  for  example,  which  is  formed  of  the 
lightest  plants,  as  the  equisita'ceee,  ferns,  &c.,  cannot  be,  in  the  bed,  more 
than  thirty-nve  thousands  of  the  thickness  of  the  rail  that  formed  it :  that 
is,  a  coal-bed  of  from  one  or  two  to  thirty  yards  thick,  would  require  the 
rafts  to  have  been  twenty-eight  or  fifty-seven,  to  eight  hundred  and  fifty- 
seven  yards  in  thickness,  which  evidently  exceeds  the  limits  of  probability,, 
and  in  most  seas  would  be  impossible. 

The  idea  of  the  formation  being  analogous  to  that  of  peat-bogs  does  not 
present  this  difficulty,  arid  only  requires  lime  for  the  accumulation  of  the 
necessary  organic  materials.  In  the  present  state  of  things,  this  time  would 
be  very  considerable;  for,  according  to  the  calculation  of  M.  de  Beaumont, 
on  the  quantity  of  carbon  annually  produced  by  our  forests,  not  much  more 
than  six-tenths  of  in  inch  in  thickness  of  coal  would  be  formed,  in  carbo- 
na'ceous  deposits,  in  the  period  of  a  century.  But  everything,  leads  to  the 
belief,  that  at  a  mean  temperature  of  71°  (Fahrenheit),  when  the  atmosphere 
was  filled  with  vapour,  and  vegetation,  in  the  genera  of  plants  that  then 
grew  in  our  country,  was  infinitely  more  vigorous  than  at  present :  we  are 
also  led  to  believe  that  at  the  epoch  of  these  formations,  when  the  earth  had 
not  yet  cooled  to  its  present  temperature,  a  great  deal  of  carbonic  acid 
issued  from  its  interior,  and  the  appropriation  of  the  carbon  by  plants  was 
then  more  rapid.  It  is  not  only  for  the  formation  of  coal  that  a  long  period 
of  time  is  required  ;  all  sedimentary  and  calcareous  deposits  formed  only  of 
shells,  which  acquire  much  greater  thickness  than  carbona'ceous  deposits, 
have  certainly  required  many  centuries  to  reach  this  point. 

The  hypothesis  which  assimilates  deposits  of  coal  to  peat-bogs,  is  fortified 
by  the  different  characters  they  present;  such  are,  not  only  the  trees  found 
erect  with  their  roots,  and  the  remarkable  preservation  of  the  leaves  in 
schists,  but  the  deposition  in  isolated  basins,  of  greater  or  less  extent,  seems 
to  indicate  swarnps  and  marshy  places  formed  in  depressions  of  the  surface 
of  the  soil.  These  deposits  are  often  surrounded  on  all  sides  by  rocks  of  an 
anterior  formation,  which  form  the  parietes  of  the  cavity  where  they  took 
place ;  frequently,  we  also  find  that  a  certain  number  of  small  basins,  inde- 
pendent of  each  other,  forming  part  of  a  more  extensive  basin  of  a  species 
of  lake  filled  with  contemporaneous  arena'ceous  matters,  on  the  surface  of 
which  there  would  be  formed  as  many  masses  of  combustible.  There  are 
some,  too,  that  extend  through  the  length  of  certain  ancient  valleys,  and  are 
contained  in  them.  All  these  circumstances  are  observable  in  the  deposits 
of  the  centre  and  south  of  France ;  but  in  the  north  of  France,  in  Belgium, 
in  England,  and  in  Scotland,  it  is  different.  There,  the  beds  of  combustible 
seem  to  extend  over  great  spaces ;  and  the  assemblage  of  facts,  as  well  as 
the  immediate  superposition  of  marine  limestone,  found  in  all  these  countries, 
leads  us  to  suppose  that  these  deposits,  now  dislocated  and  separated  by  seas, 
have  once  formed  part  of  the  same  whole.  It  was  not  in  swamps  or  in 
closed  lakes  they  were  formed,  but  in  a  vast  sea,  the  receptacle  of  all  the 
debris  of  the  vegetation  of  its  coasts  and  islands,  that  they  must  have  taken 
place,  and  in  which 'undulatory  motion  stratified  these  materials  as  well  as 
all  other  sedimentary  deposits. 

Certain  deposits  of  lignite  were  evidently  formed  in  the  same  manner  as 
coal ;  but  there  are  others  which  constitute  irregular  masses  of  wood  thrown 


154  UPHEAVAL  AND  SUBSIDENCE. 

pell-mell,  more  or  less  bituminous  and  preserving  their  tissue,  found  acci- 
dentally buried  in  the  midst  of  sedimentary  deposits,  and  which  probably 
had  a  similar  origin  to  those  transported  by  great  rivers,  which  are  deposited 
in  lakes  or  conveyed  to  the  middle  of  seas. 

Remains  of  shells  are  rare  in  deposits  of  coal,  properly  so  called.  There 
is  no  trace  of  them  in  any  of  the  deposits  of  the  centre  of  France ;  and  it 
is  only  in  the  great  formation  comprising  the  north  of  France,  Belgium, 
and  England,  that  some  examples  are  met:  marine  shells  are  found  in  the 
environs  of  Liege  and  of  Namur,  in  Derbyshire,  &c.  Fresh-water  shells, 
similar  to  u'nio  and  anodo'nta,  are  found  in  the  same  place.  In  most  depo- 
sits of  lignite,  in  which  the  structure  of  the  wood  has  generally  disappeared, 
we  find,  on  the  contrary,  a  great  number  of  fluviatile  shells,  which  proves, 
that  the  formation  of  these  deposits  took  place  in  fresh-water  lakes. 

EFFECTS    ATTRIBUTABLE    TO    UPHEAVAL    AND    SUBSIDENCE. 

7.  At  whatever  height  we  may  find  fluviatile  deposits  on  the 
surface  of  the  globe,  there  is  nothing  to  excite  astonishment;  for 
we  readily  conceive  that  lakes  could  have  existed  at  all  heights  on 
continents,  and  that  after  their  waters  flowed  away  their  deposits 
remained  dry  on  the  soil.  But  we  find  also  marine  deposits  at  all 
heights,  in  very  extensive  beds,  and  at  first  sight  it  is  not  so  easy  to 
account  for  them.  It  is  evident  that  such  deposits  could  have  been 
formed  only  under  waters  of  the  sea ;  and,  as  they  are  now  found 
thousands  of  yards  above  the  present  level  of  the  ocean,  we  must 
admit  one  of  two  things;  either  that  the  water  was  elevated  above 
these  points  for  a  sufficiently  long  time  to  form  thick  beds  there, 
or  that  these  deposits  were  raised  up  from  the  bottom  of  the  sea  to 
the  height  we  now  find  them.  Nothing  in  the  phenomena  of  the 
present  time  warrants  a  belief,  that  the  sea,  which  has  not  changed 
its  level  within  the  time  of  history,  could  have  been  so  elevated, 
long  enough  to  form  considerable  deposits.  The  universal  deluge 
of  the  Holy  Scriptures  was  a  catastrophe  of  short  duration,  and 
therefore  could  not  have  produced  the  immense  deposits  referred 
to,  which,  everything  leads  us  to  believe,  were  formed  slowly. 
Besides,  this  catastrophe  is  comparatively  of  modern  date,  and 
must  be  referred  to  the  last  modification  of  the  surface ;  now,  all 
the  deposits  of  shells  of  which  we  speak  were,  long  anterior,  and 
were  independent  of  facts  belonging  to  the  history  of  the  human 
race.  Nothing  informs  us  what  became  of  the  excess  of  water  (a 
greater  or  less  volume  than  now  exists)  above  the  present  level, 
without  having  recourse  to  divine  interference,  which  must  have 
been  frequent  in  ancient  times,  to  cause 'these  waters  to  appear  or 
disappear  a  great  many  times,  and  even  suspend  the'  action  of  the 
laws  of  equilibrium.  In  fact,  very  often  deposits  of  shells,  seen 
here  and  there  at  a  great  height,  are  not  found  on  corresponding 
summits,  and  are  represented  on  the  contrary  with  all  their  charac- 
ters, thousands  of  yards  lower  down ;  hence  we  must  suppose  the 

7.  How  is  the  presence  of  marine  shells  in  deposits,  at  great  heights 
above  the  present  level  of  the  sea,  accounted  for  ? 


SHELL    DEPOSITS.— RAISED  BEACHES.  155 

waters  were  considerably  elevated  on  the  first  of  these  points,  and 
remained  low  on  the  other,  which  is  absurd,  or  we  must  admit  that 
the  same  animals  could  live  in  one  place,  near  the  surface  of  the 
water,  and  in  another,  at  immense  depths,  which  is  contrary  to  all 
observation.  Therefore,  the  only  reasonable  supposition  left  is,  that 
of  upheaval;  an  idea  supported  at  least  on  positive  events  which 
have  taken  place  in  our  own  times,  and  which  are,  doubtlessly,  not 
the  only  ones  which  have  been  manifest  on  the  surface  of  the 
globe.  If  an  upheaving  force  could  suddenly  elevate  200  leagues 
of  the  coast  of  Chile  (page  99),  spreading  as  far  as  the  islands  of 
Juan  Fernandez;  if  the  same  effect  were  slowly  produced  in  all 
the  gulf  of  Bothnia,  in  Sweden,  and  in  Finland,  over  a  surface  of 
not  less  extent,  we  may  comprehend  how  vast  countries  might  have 
been  elevated  anywhere.  The  enormous  liquified  mass  forming 
the  interior  of  the  globe,  oscillating  from  side  to  side  beneath  its 
thin  crust,  could  emboss  it  in  every  direction,  and  nothing  more 
would  be  required  to  raise  continents  out  of  the  sea,  and  vary  the 
slight  relief  in  all  manners.  And  let  not  such  effects  excite  alarm 
because  they  appear  gigantic;  we  judge  them  to  be  so  because 
we  compare  them  with  our  feeble  powers,  for  they  are  nothing 
compared  to  the  globe  itself.  What  are  the  25,660  feet  in  the 
height  of  Himalaya,  the  highest  mountain  in  -the  world,  and  the 
24,580  feet  depth,  the  deepest  soundings  in  the  midst  of  the  sea, 
compared  with  the  19,685,500  feet,  measured  by  the  mean  radius 
of  the  earth  ?  And  notwithstanding  such  eminences  or  depths,  the 
sum  of  which  is  less  than  .5000  of  an  inch  to  the  yard,  are  rarities 
on  our  planet,  whose  inequalities  are  not  even  comparable  to  the 
unperceivable  irregularities  which  are  formed  in  our  manufactories 
on  moulded  glass  or  metals,  which  nevertheless  pass  unnoticed. 
If  to  these  reflections  we  add  our  knowledge  of  the  immense  force 
often  exerted,  from  the  interior  towards  the  exterior,  none  of  these 
phenomena  will  astonish  us.  . 

8.  Shell  deposits,  and  upheaved  or  raised  beaches. — Parts  of 
soil  upheaved  above  the  level  of  the  sea,  are  characterized,  on  the 
surface  of  exposed  rocks,  by  the  presence  of  various  shells,  that 
live,  ordinarily,  attached  on  a  level  with  the  water,  such  as  barna- 
cles, mussels,  &c. ;  or  by  that  of  some  small  -deposits  of  shells, 
identical  with  those  daily  formed  at  the  bottom  of  neighbouring 
seas.  Now,  on  examining  the  hills  near  the  coast  of  Chile,  there 
has  been  found  on  the  plateaux  (which  succeed  each  other  in  ter- 
races, the  sides  of  which  are  parallel  to  the  present  shores),  shells 
similar  to  those,  that  have  been  left  dry  in  our  day,  and  which  are 
.  still  attached  to  rocks,  as  well  as  shelly  deposits,  which  contain  the 
same  organic  remains  as  those  now  forming  in  the  Pacific  Ocean. 
Is  it  not  most  probable  that  these  deposits  are  indications  of  suc- 
cessive upheavals,  similar  to  those  which  have  recently  taken  place? 

8.  How  are  raised  beaches  accounted  for  ? 


156  EVIDENCE  OF  SUBSIDENCE. 

This  inference  is  sustained  by  observations  made  on  the  coast  of 
Peru,  near  Lima,  in  the  island  of  San  Lorenzo,  where,  thirty  yards 
above  the  level  of  the  sea,  deposits  have  been  found  which  contain 
woven  osier,  portions  of  cotton  thread,  &c.,  clearly  showing  that  the 
deposits  in  question  were  formed  since  the  existence  of  man  in 
those  countries;  as  the  level  of  seas  has  not  changed  since  history 
began,  it  is  only  by  upheaval  they  could  be  brought  to  light. 

That  the  coast  of  Sweden  has  been  uplifted  slowly,  has  been  established 
by  the  most  exact  observations.  In  digging  a  canal  near  Stockholm,  in  the 
midst  of  beds  of  sand,  clay,  and  marl,  filled  with  shells  similar  to  those  that 
now  live  in  the  Baltic,  there  were  found  the  remains  of  very  ancient  ves- 
sels;  all  this  country,  which  must  have  been,  at  some  period,  under  water, 
and  in  which  some  ships  were  wrecked,  has  been  upheaved  since  the  pre- 
sence of  man  ;  the  level  of  the  ocean  being  invariable.  It  is  therefore  evi- 
dent that  the  shelly  deposit  of  Uddewalla,  in  which  organic  remains  of  the 
Baltic  are  found,  seventy  yards  above  the  level  of  the  sea,  and  in  which  M. 
Brongniart  found  balani  attached  to  rocks,  as  they  are  on  the  present  coast, 
is  a  fact  of  elevation.  Similar  deposits  and  evidence  of  elevation  are  met  in 
other  parts  of  the  world.  The  upheaval  and  subsidence  of  the  temple  of 
Serapis  has  been  already  mentioned  (page  19). 

In  thus  admitting  that  very  extensive  deposits,  formed  of  shells  that  are 
now  living  in  the  sea,  have  been  evidently  upheaved  to  greater  or  less  heights, 
is  it  not  therefore  exceedingly  probable  that  the  same  is  true  of  all  the  rest  ? 
Why  should  this  not  be  true  in  regard  to  the  neighbourhood  of  London  and 
Paris;  to  that  of  the  plains  of  Gascony,  Austria,  Hungary,  Poland,  &,c.  ? 
All  the  shells  found  in  those  places  are  not  similar  to  those  in  the  pre- 
sent seas;  but  there  exists  a  considerable  quantity  of  them,  and  moreover, 
their  preservation  is  so  perfect,  in  many  places,  that  they  seem  to  have  been 
recently  buried.  If  we  admit  the  fact  of  elevation,  for  these  deposits,  can 
we  refuse  it  to  the  chalk  that  everywhere  envelopes  them,  forming  not  only 
the  Jura,  but  a  great  part  of  the  calcareous  mountains  of  France  ;  or  to  any 
shell-deposits,  the  organic  debris  of  which  bear  witness  to  their  marine 
origin  ? 

9.  Subsidence  of  various  deposits. — Upheaval  has  been  shown ; 
subsidence  is  not  less  demonstrable.  At  many  points,  on  the  coasts 
of  France  and  England,  may  be  seen,  at  low  tide,  very  extensive 
deposits  of  plants,  similar  to  those  now  living  in  those  countries, 
and  which  appear  to  have  grown  on  the  spot  where  they  are  found, 
for  the  roots  are  seen  attached  to  the  soil.  These  deposits  rest  on 
earthy  matter,  covered  with  leaves,  heaped  upon  each  other,  or 
sunk  in  a  peat-like  substance.  In  these  places  have  been  found 
birch-trees,  chestnuts,  oaks,  and  fir-trees,  sometimes  scarcely 
altered,  species  of  deer,  similar  to  those  met  in  peat-bogs;  the 
whole  covered  by  argillaceous  deposits,  which  contain  fresh-water 
shells.  These  submarine  forests,  as  they  are  called,  could  have 
grown  only  on  a  soil  more  or  less  elevated  above  the  sea  ;  and  as 
they  are  now  found  beneath  it,  and  are  not  uncovered,  except  in 
unusually  low  tides,  the  earth  must  have  sunk,  after  the  period  of 
regetation.  The  dirt-bed  of  Portland  (fig.  225,  p.  145)  shows  the 

9.  What  are  submarine  forests  ?  How  is  the  subsidence  of  deposits 
proved  ? 


SUBSIDENCE  OF  VARIOUS  DEPOSITS. 


157 


existence  of  a  vegetable  earth  or  mould,  of  a  soil  nearly  dry,  resting 
on  marine  deposits.  This  bed  has  been  covered  by  a  very  thick 
deposit  of  lacus'trine  limestone,  and  the  whole  passes  under  the 
green  sand  which  precedes  the  chalk,  and  which  is  of  marine  for- 
mation. It  is  clear,  therefore,  that  there  was  in  those  places  a  cer- 
tain upheaval  of  the  inferior  marine  limestone,' on  which  terrestrial 
plants  grew ;  that  subsequently  a  lake,  or  a  deep  estuary,  \vas 
formed,  in  which  beds  of  limestone,  sand,  and»clay,  were  deposited, 
filled  with  fluviatile  shells,  the  entire  mass  being  sometimes  from 
200  to  500  yards  in  thickness.  A  subsequent  upheaval  must  have 
lifted  the  whole  to  its  present  level. 

Around  the  Paris  basin,  the  deposit  of  marine  limestone,  worked  for  build- 
ing  stone,  must  have  been  at  first  uplifted,  at  various  points,  above  the  sea, 
to  be  covered  by  a  fresh- water  lake  in  which  lacustrine  deposits  were  formed, 
and  among  them  the  plaster  of  Paris  ;  subsequently,  it  must  have  been  sunk 
beneath  the  sea,  to  be  covered  by  a  marine  formation,  and  again  uplifted,  to 
be  covered  by  a  second  fresh- water  formation. 


Fig.  251. — Impressions  of  feet  of  quadrupeds. 

Hundreds  of  facts  of  this  kind  might  be  cited  ;  but  we  will  only  notice  tho 
impressions  of  feet  and  tracks  of  certain  quadrvpeds  (Jig.  251)  found  at  Hess- 

berg,  near  Hildburghausen,  in  Saxony, 
on  the  faces  of  certain  beds  of  sand- 
stone, and  the  impressions  of  the  feet 
of  various  birds,  found  in  the  valley  of 
the  Connecticut,  in  the  United  States, in  the 
same  deposits  (fig.  252).  These  impres- 
sions show  that  the  soil  was  in  a  degree 
soft,  although  partly  dry,  which  is  proved 
by  the  ridges  it  presents,  and  that  it  was 
out  of  water;  the  sedimentary  bed  on 
which  these  animals  walked,  is  now  co- 
vered by  another,  which  is  moulded  on 
these  tracks,  and  afterwards  by  considera- 
ble deposits  of  the  same  matter  which  could 
be  formed  only  under  water;  it  follows, 
therefore,  that  the  soil,  first  uplifted  enough 
to  enable  terrestrial  animals  to  walk  on  it, 
was  subsequently  sunk  to  receive  all  those 
sedimentary  deposits,  and  afterwards  was 
Fig.  252. — Bird  tracks.  again  upheaved  to  its  present  position. 

14 


158  CHANGE  OF  POSITION  OF  STRATA. 

CHANGE    OF    POSITION    AND    DISLOCATION    OF    STRATA  ATTRIBUTABLE 
TO    UPHEAVAL. 

10.  It  has  been  already  stated  that  sand  and  shells  are  deposited, 
under  water,  in  horizontal  beds.  Indeed,  we  frequently  find  them 
in  this  position  on  the  surface,  even  over  extensive  spaces,  and  we 
then  find  flattened  pebbles,  valves  of  oysters,  and  othershells,  lying 
flat,  and  turrieulated  shells  lying  on  one  side  ;  and  everything  eon- 
firming  the  idea  of  a  slow  formation,  by  the  weight  of  these  sub- 
stances.  But  it  sometimes  happens  that  we  see  deposits,  more  or 
less  inclined  in  certain  parts  of  their  extent,  raised  .up  almost  to  a 
vertical  position,  and  sometimes  entirely  overturned  ;  they  stilJ 
preserve,  however,  all  the  characters  which  show  they  were  at  first 
horizontal,  for  the  debris  of  shells  and  pebbles  they  contain  are  still 
found  arranged  parallelly  to  the  planes  of  the  beds.  Besides,  there 

are  deposits  which  contain  ge'odes 
of  agate,  in  which  are  found  sta- 
Ja'cthes  with  the  axis  more  or  less 
_  inclined  (fig.  253),  which  is  di- 
lectly  opposite  to  the  manner  of 
production   of  these  substances. 
-  Consequently,  these  deposits  could 
Fig.  253.  Fig.  254.        not  have  been  formed  in  the  posi- 

tion we  find  them,  for,  on  the  one  hand,  the  debris  of  shells  and 
pebbles  would  have  rolled  over  to  be  surely  balanced,  or  fallen  to 
the  foot  of  the  ta'his  ;  on  the  other,  the  stalac'tites  would  have  formed 
in  a  vertical  position.  This  last  observation,  particularly,  shows 
that  the  beds  were  at  first  horizontal  (Jig.  254),  and  that  their  posi- 
tion has  been  changed  subsequently  to  their  formation ;  this  is  one 
of  the  great  geological  phenomena  we  seek  to  explain. 

The  effects  of  earthquakes,  and  those  of  volcanic  phenomena,  will  serve  as 
points  of  comparison  in  our  inquiry.  On  one  hand,  the  crevices  produced 
in  the  soil  at  the  time,  t»  a  greater  or  less  depth,  can  only  be  the  effect  of 
upheaval ;  for  the  separation  of  parts  does  not  result  here  from  drying-,  nor 
from  cooling,  which  would  produce  a  retreating  of  the  whole  mass.  It  is 
remarked,  in  the  neighbourhood  of  cracks,  that  the  soil  is  no  longer  on  the 
same  plane  as  the  rest  of  the  country;  that  it  is  moie  or  Jess  arched,  and 
often  one  part  is  more  elevated  than  another.  Now,  if  the  soil  haye  been 
uplifted,  it  must  follow  that  the  internal  beds  have  been  dist»rbed  in  their 
position  ;  consequently,  when  in  a  formation  of  horizontal  strata,  a  crack  is 
made  in  a  straight  line  (fig.  255),  the  beds  must  be  inclined  on  both  sides 
throiagh  their  length,  like  the  two  slopes  of  a  roof.  When  several  divergent 
cracS  are  formed  (».256),the  beds  ought  to  incline  symmetrically  around 
the  axis  of  elevation. 

Now,  if  we  find  all  inclined  beds  in  one  or  the  other  of  these  positions, 
we  have  a  right  to  conclude  they  have  been  uplifted  by  the  same  causes. 
11.  Faults.— When  a  crack  is  made,  it  often  happens  that  one 

10.  What  proves  that  the  position  of  strata  has  been  changed  by  up. 
heaval? 


FAULTS. 


159 


Fig-,  255, 

of  the  parts  of  the  soil  is  more  elevated  than  the  other,  no  matter 
whether  the  crack  remains  open  or  not.  These  effects  are  often 
observed,  a«d  it  is  presumed  they  are  all  produced  by  the  same 
cause,  namely,  upheaval.  The  beds  are  then  inclined  in  opposite 
directions  (Jig-  257),  and  one  of  the 
parts  is  more  elevated  than  that  which 
is  adjacent ;  the  junction  is  sometimes 
distinguished  by  subterraneous  work, 
either  subsequently  filled  with  gravel, 
or  a  slight  fissure,  or  at  least  by  a 
surface  of  separation,  the  planes  of 

which  are  smooth,  and  sometimes  polished  or  striated  vertically, 
showing  a  close  crack  and  a  rubbing  of  one  part  on  the  other. 
This  arrangement  has  been  called  fault  (from  the  German  fall,  an 
accident, /a//,  or  sinking),  because  one  part  is  lower  than  the  other; 
faults  are  observed  in  every  kind  of  soil,  and  present  crests  or 
ridges  extending  over  great  spaces,  nearly  in  a  straight  line,  some- 
times broken  here  and  there,  but  the  different  parts  preserve  the 
same  direction. 

12.  Besides  showing  themselves  on  the  surface,  faults  are  also 
perceived  under  ground,  by  the  disturbance  they  have  caused  in 
beds  or  veins  worked  for  the  benefit  of  the  arts.  It  is  thus,  for 
example,  in  coal  measures,  the 
same  bed  of  coal  a,  6,  c  (Jig-  258), 
is  found  so  much  deranged  in  its 
position,  that  the  miner,  after 
having  worked  on  a  part  of  its 
direction,  from  d  to  c,  for  instance, 
finds  it  suddenly  end,  and  would  Fig- 258.— Bed  dislocated  by  faults. 
f\l  once  abandon  all  his  labours,  had  not  experience  taught  him  that, 
by  following  the  fault,  he  will  find  the  deposit  either  above  or 
below  the  point  where  it  abruptly  terminated.  Sometimes  there 
results  from  these  disturbances  serious  mistakes  for  speculators; 

11.  What  is  meant  by  a  fault?     How  are  faults  produced  ? 

12.  Do  faults  always  show  themselves  on  the  surface  ? 


160 


CRATERIFORM  DISPOSITION, 


observing  various  outcrops  on  the  surface  of  the  ground,  «,  b,  c,  d 
(Jig.  259),  they  have  inferred  the  existence  of  as  many  different 


fig.  259.  —  Dislocation,  causing  a  single  bed  to  appear  as  several. 


beds,  and  consequently  great  wealth,  when,  in  reality,  it  was  only 
one  and  the  same  bed  dislocated  and  raised  up  to  different  levels 
by  successive  faults. 

13.  Crate'riform  disposition.  —  The  known  formation  of  Monte- 
Nuovo,  in  explaining  to  us  the  uplifting  of  the  beds  seen  in  its 
crate'riform  cavity,  leads  us  to  attribute  also  to  upheavals,  the 
epochs  of  which  are  unknown,  the  structure  of  several  other  hil- 
locks of  the  same  country,  such  as  those  of  the  solfata'ra  of  Puz- 
zuoli,  of  Camboldi,  of  Astroni,  &c.,  where  the  strata  are  all  raised 
towards  the  axis  of  the  excavation  found  in  the  centre.  In  these 
hillocks,  the  bottom  of  the  cavity,  particularly  at  Astroni  (Jig.  260), 
presents  the  point  of  a  tra'chytic  dome,  which  doubtlessly  caused 
the  elevation  of  the  surrounding  beds  of  pumice  tu'fa.  These 
crater  hillocks  at  once  explain  all  those  of  the  Champs-Phlegreens, 
which  are  full  at  the  top,  but  all  the  strata  of  which  are  raised 
around  the  axis  (fig.  261)  ;  probably  there  would  be  found  at  their 


Fig.  260. — Cr a le'r if orm  disposition,  with       Fig.  261. —  Hillock  with  strata 
a  tra'chytic  hillock  in  the  centre.  raised  toicards  the  summit. 

base  some  point  of  a  cone  which  had  not  been  uplifted  with  suffi- 
cient force  to  crack  the  summit.     When  strata 
are  inclined  in  opposite  directions  (Jig.  261), 
like  the  two  sides  of  a  roof,  they  form  what  is 
termed  an  anteclinal  axis ;  but  when  they  dip 
Fig.  262.    ,      oppositely,  it  is  termed  a  synclinal  axis  (fig.  262). 
Similar  circumstances  are  observed  in  many  places,  on  a  greater 
scale.     At  Cantal  and  Monte-Dore,  basa'ltic  and  tra'chytic  beds, 
which  could  only  have  been  deposited  on  a  horizontal  plane,  are 
found  raised  up  around  one  or  more  centres,  leaving  towards  their 

point  of  convergence  a  crate'riform. 
basin  of  more  or  less  extent,  or 
rising  around  a  more  or  less  pro- 

^ ^ jecting  tra'chytic  dome  (fig.  263), 

elevated  around  a  Me  the  Peak  of  Teneriffe,  above 
tra'chytic  dome.  the   escarpments   surrounding  it. 

13.  What  is  meant  by  an  anteclinal  axis  ?     What  is  a  synclinal  axis  ? 


VALLEYS  OF  ELEVATION. 


161 


Granitic  masses  are  found  under  similar  circumstances,  in  the 
midst  of  which  rise  hillocks  of  basa'lt  or  scoriae,  which  doubtlessly 
followed  the  first  explosion,  as  at  Monte-Nuovo  and  the  island  of 
St.  George. 

14.  Calcareous  countries  are  not  more  exempt  from  these  acci- 
dents than  others;  only  the  crate'riform  cavities,  in  place  of  being 
nearly  circular,  are  more  frequently  elliptical,  sometimes  very 
much  elongated,  as  seen  in  the  Jura  mountains.  In  general,  the 
length  is  produced,  like  cracks,  extending  to  a  great  distance,  and 
forming  along  its  direction  elongated  hillocks,  in  a  line  with  each 
other,  offering  here  and  there  more  projecting  summits.  These 
summits  are  most  frequently  rent,  and  present  what  are  termed 
dosed  valleys,  and  valleys  of  elevation  (Jig.  264),  which  are  in 
fact  craters  of  elevation. 


Fig.  264. — Plan  of  a  crater  of  elevation  in  calcareous  countries. 

15.  Ruptures  of  calcareous  mountains  do  not  always  present  the 
crate'riform  uniformity  just  indicated,  but  vary  much,  in  this  re- 
spect. One  side  of  the  rupture  sometimes  remains  low,  while  the 
other  is  elevated,  as  represented  (Jig.  265).  Sometimes  the  supe- 
rior beds  seem  to  have  retired  horizontally,  and  the  inferior  strata 
are  arched  up  between  the  fractured  extremities,  as  seen  (fig.  266). 


Fig.  265.  Fig.  266. 

Craters  of  elevation  in  calcareous  formations. 

Often,  among  the  upheaved  beds,  some  are  found  which  are  easily 
disintegrated,  and  their  projection  soon  tumbles,  inducing  the  fall 
of  solid  strata ;  from  this  we  have  ridges  of  rock  parallel  to  each 
other,  separated  by  little  valleys,  in  which  the  rain-water  flows,  and 
they  become  covered  by  vegetation  ;  in  this  case  the  general  ridge 
of  the  mountain  is  as  represented  (fig.  267).  Sometimes  the 
summit  only  presents  a  mass  of  calcareous  blocks  piled  one  on  the 
other,  but  arranged  in  line,  as  if  the  work  of  a  mason.  Again, 

14.  What  are  valleys  of  elevation  ?     What  is  the  peculiarity  of  crate'ri- 
fbrm  cavities  in  calcareous  countries  ? 

15.  Are  the  crate'riform  cavities,  in  calcareous  countries,  always  uniform 
in  configuration  ? 


162 


UPHEAVAL  WITHOUT  DISLOCATION. 


when  two  parallel  upheavals  take  place  (fig*  268),  it  sometimes 
happens  that  one  portion  (a)  of  the  formation  is  cut  off,  and  then 


Fig.  267.  Fig.  268. 

Various  disjwsitions  of  craters  of  elevation  in  calcareous  formations. 

forms  the  culminating  point  of  the  whole  mass,  giving  the  appear- 
ance of  a  repetition  of  certain  strata  in  the  same  deposit.  The 
central  part  of  the  uplifted  mass  is  formed  of  matters  sometimes 
analogous  to  those  that  essentially  constitute  the  formation,  and 
sometimes  totally  different. 

16.  Upheaval  and  distortion  without  dislocation. — The  uplift- 
ing of  strata  is  often  accompanied  by  ruptures,  but  frequently  there 
is  no  apparent  dislocation.  We  have  already  noticed  the  isolated 
mounts  or  hillocks  on  the  Champs-Phlegreens  (Jig.  261),  and  the 
same  is  also  seen,  for  greater  or  less  lengths,  which  then  have 
more  or  less  projecting  sides,  or  anleclinal  lines,  formed  by  the 
uplifted  strata  on  either  side,  like  the  dip  of  a  roof;  these  effects 
are  similar  to  those  produced  by  crevices  ;  but  acting  on  strata  of 
a  certain  degree  of  flexibility,  like  the  matters  placed  in  the  centres 
of  the  preceding  figures.  The  Jura  mountains  present  a  number 
of  instances  of  this  ;  we  often  see  there  different  parallel  ridges  of 
this  kind,  clearly  marked  on  the  simplest  maps,  which  leave  be- 
tween them  valleys  of  greater  or  less  breadth,  on  the  two  slopes  of 
which  the  beds  are  uplifted.  The  result  is  great  undulations  in 
the  strata,  remarked  especially  in  escarpments,  produced  by  diffe- 
rent ruptures,  which  cut  the  ridges  in  a  great  many  places.  These 


Fig.  269. — Distortions  of  the  Jura.     Valleys  from  plaiting. 


,  16.  Is  upheaval  always  attended  by  rupture  of  strata? 
clinal  lines?     How  are  undulations  in  strata  produced  ? 


What  are  ante- 


PLAITING  OF  SCHISTOSE  STRATA, 


163 


undulations  on  a  grand  scale,  represented  Jig.  269,  are  not  inter- 
rupted except  by  crate'riform  ruptures  of  summits,  previously 
spoken  of. 

17.  Plaiting  or  folding  of  schistose  strata.  —  Distortions  are 
also  observed  under  other  circumstances,  in  which  it  seems  that 
beds  of  a  degree  of  flexibility,  or  in  a  pasty  condition,  have  been 
compressed  by  two  opposing  forces,  rather  than  uplifted.  Certain 
facts  observed  in  matter  of  the  structure  of  schist,  naturally  lead  to 
this  idea.  It  often  happens  that  the  laminse  of  these  deposits,  instead 
of  continuing  on  the  same  plane,  horizontal  or  inclined,  are  all  found 
very  much  contorted  without  ceasing  to  be  parallel,  or  folded  on 
themselves  into  a  more  or  less  acute  zig-zag  (Jig.  2^0).  The  sup- 
position as  to  the  mode  in  which  this  plaiting  has  been  effected,  has 
been  verified  by  experiments  made  by  Sir  James  Hall. 


Fig.  270. — Contortion  of  schists. 


Fig.  271. — Contortion  of  coal. 


Entirely  similar  circumstances  occur  in  coal  measures ;  all  the  strata  of 
these  deposits,  both  argilla'ceous  and  combustible,  are  found  plaited,  and 
often  at  acute  angles  (Jig.  271) :  this  is  especially  remarkable  in  the  coal 
measures  near  Mons,  in  Belgium. 

Now,  how  did  these  compressions  take  place  ?  In  a  degree,  an  explana- 
tion is  required  for  each  locality;  but  we  know  that  in  a  deposit  of  inclined 
strata,  the  mass  of  which  is  pushed  from  below  upwards,  the  superior  part 
presses  with  all  its  weight  on  the  inferior,  and  the  beds  of  the  latter,  being 
placed  between  two  opposing  forces,  may  fold  on  themselves,  if  they  are 
sufficiently  flexible.  On  the  other  hand,  as  matters  in  a  state  of  fusion  arc 
often  injected  with  great  force  into  sedimentary  deposits,  it  is  conceived  that 
from  this  results  the  lateral  compression  which  produces  the  same  effects. 

18.  Origin  of  Valleys. — If. mountains  are  only  the  result  of  dis- 
locations which  have  taken  place  on  the  surface  of  the  globe,  by 
the  force  of  internal  agents,  there  would  be  no  difficulty  in  account- 
ing for  valleys.  The  first  idea  of  the  origin  of  valleys  was  based 
on  excavation  by  the  erosive  action  of  water ;  but  then  mountains 
having  been  previously  formed,  it  is  clear  that  water  Avould  always 
follow  the  natural  slope  of  the  soil,  and  only  excavate  in  that  direc- 

17.  How  is  the  folding  in  schistose  strata  accounted  for? 

18.  How  are  valleys  produced?     What  is  meant  by  valleys  of  disloca- 
tion ? 


Ifi4  ORIGIN  OF  VALLEYS. 


tion ;  when  arrested  by  any  obstacle,  or  in  a  basin,  it  would  of 
preference  cut  through  deposits  of  sand  and  gravel.  We  see  the 
contrary  of  this  natural  action  :  valleys  do  not  generally  follow  the 
real  slope  of  the  soil ;  it  is  not  by  the  lowest  part  of  basins  that 
waters  are  generally  turned,  nor  through  moveable  formations  that 
they  make  a  passage.  Rivers,  in  place  of  having  excavated  their 
beds,  as  was  thought,  are  simply  directed  by  the  canals  they  found 
already  made.  Now  it  is  not  difficult  to  go  back  to  the  origin  of 
these  canals ;  they  are  evidently  the  result  of  upheavals,  which 
have  embossed  or  ridged  the  soil,  until  then  horizontal.  It  is  clear 
the  inflexible  beds  must  have  been  broken,  and  consequently  a 
number  of  cracks  were  formed,  as  in  the  transverse  section  (jig. 
272).  The  cracks  became  valleys,  placed  in  different  relations  to 


Fig.  272. — Production  of  valleys  by  dislocation. 

each  other  according  to  circumstances  of  upheaval:  parallel  if  the 
action,  taking  place  in  a  certain  direction,  extended  a  sufficient 
length  ;  divergent,  if  the  action  occurred  at  one  point,  as  in  certain 
massive  mountains  ;  often  perpendicular  to  the  direction  of  uplifted 
chains,  as  the  secondary  cracks  manifested  during  earthquakes 
(fig.  255),  which  occurs  especially  when  the  internal  action  forces 
crystalline  matter  through  the  principal  crack.  It  may  be  easily 
conceived  that  crevices  would  remain  more  open  in  solid  matters 
than  in  arena'ceous  deposits,  the  falling  of  which  would  tend  to 
fill  the  vacancy ;  and  this  is  the  reason  why  rivers  seem  to  shun 
moveable  formations,  which  they  could  easily  excavate  if  they  had 
not  found  a  bed  ready  prepared  in  another  direction. 

19.  It  must  not  be  concluded,  however,  that  water  has  no  agency 
in  the  configuration  of  valleys.  On  the  contrary,  we  must  believe 
that  when  a  country  has  been  suddenly  rent,  causing  the  accumu- 
lated waters  to  flow  all  at  once,  that  torrents  of  frightful  power 
were  produced,  tearing  away  and  removing  all  parts  fractured  by 
upheaval,  and  they  thus  modified  the  passages  offered  to  them. 
It  is  probable,  also,  that  certain  valleys,  which  pass  through  a 
moveable  formation,  little  disposed  to  fracture,  have  been  produced 
exclusively  by  water.  Valleys  referable  to  this  origin  are  very 
different  in  character  from  the  first :  they  follow  the  natural  line 
of  slope  ;  they  change  their  course  on  meeting  masses  which  offer 
resistance,  and  turn  round  them  to  remain  constantly  in  the  movea- 
ble deposits.  Such  are  the  valleys  which  cut  through  the  great 
deposits  of  rolled  flints  found  at  the  foot  of  the  oriental  Alps. 

19.  How  are  valleys  of  erosion  produced  ? 


ORIGIN  OF  CAVERNS.  165 

Many  great  rivers  have  themselves 

cut  their  beds  in  the  ancient  allu'- 

vium  (fig.  273),  very  different  from 

that  now  forming;  the  Seine,  at  Pa-    _ 

ris,  excavated  its  bed  in  a  deposit    t- 

of  rolled  flints  very  unlike  ths  gravel  Fig.  ^73.—  Vuthy  o/  erosion  in  a 

it  now  deposits.  moveable  formation. 

20.  Valleys  from  disruption,  are  those  which  have  been  pro- 
duced by  cracks  of  every  size,  sometimes  colossal,  during  the  up- 
heavals that  have  brought  the  land  to  its  present  configuration  of 
surface.     They  generally  present  abrupt  escarpments,  in  which 
are  seen  the  section  of  the  fractured  strata,  the  projecting  angles 
on  one  side  often  corresponding  with  the  retreating  angles  of  the 
other.     The  circles  which  frequently  terminate  them  above,  or 
those  that  divide  them  in  their  length,  are  so  many  craters  of  ele- 
vation, most  of  which  are  clearly  characterized  either  by  the  up- 
lifted strata  or  the  barrancos  they  present. 

21.  Valleys  of  subsidence  are  also  spoken  of,  but  it  does  not 
appear  there  are  any  arising  purely  from  this  cause.     Subsidence 
is  frequently  correlative  to  upheaval ;  and  valleys  as  well  as  craters 
of  elevation  may  exhibit  the  effects  of  bqth,  which  must  have  taken, 
place  especially  in  the  circles  found  along  their  line,  and  at  their 
superior  extremity. 

22.  Valleys  from  folding  or  plaiting  are  produced   by  two 
neighbouring  upheavals,  causing  the  elevation  of  strata,  and  leaving 
a  space  between,  the  slopes  of  which  being  formed  by  their  planes ; 
this  is  seen  in  the  high  parts  of  the  Jura  (fig.  269.)     Many  rivers 
flow  in  valleys  resulting  from  two  opposite  uptiltings  of  the  soil. 

23.  Valleys  of  erosion  or  denudation  are  produced  in  loose 
formations  like  ravines,  made  by  rain-storms,  the  waters  of  which 
carry  off  the  materials  constituting  the  soil. 

24.  The  origin  of  caverns  is  one  of  the  phenomena  attributed 
to  the  action  of  water ;  but,  although  we  find  on  a  level  with  the 
sea  some  caverns  of  slight  depth,  which  may  have  arisen  from  the 
repeated  action  of  waves,  it  is  difficult  to  believe  that  great  caves, 
which  are  sometimes  many  leagues  in  extent,  have  been  produced 
solely  by  the  action  of  the  waters  running  through  them.     The 
action  of  water  on  compact  limestone,  in  which  caves  are  princi- 
pally found,  is  so  slight,  that  it  has  been  supposed  the  open  spaces 
now  found,  were  at  one  time  filled  by  masses  of  salt,  which  the 
waters  had  subsequently  dissolved  and  carried  away. 

It  is  presumed,  however,  that  the  first  origin  of  caverns  is  due  to  cracks, 
produced  in  the  interior  of  the  soil,  which  have  been  afterwards  modified  by 

20.  What  are  valleys  of  disruption? 

21.  What  are  valleys  of  subsidence? 

22.  How  are  valleys  from  folding  produced  ? 

23.  How  are  valleys  of  denudation  formed  in  loose  strata? 

24.  How  is  the  origin  of  caverns  accounted  for  ? 


166  VOLCANIC  CONES  AND  LAVA  CURRENTS. 

different  causes.  We  know,  in  fact,  that  during  earthquakes,  rivers  as  well 
as  lakes  suddenly  disappear  under  ground,  sometimes  temporarily  and 
sometimes  continuously  ;  it  is  conceived  that  the  water  flows  through  internal 
cracks,  similar  to  those  produced  on  the  surface,  which  form  canals  for  its 
passage.  The  phenomenon  is  sometimes  coincident  with  the  appearance 
of  some  abundant  spring  in  a  more  or  less  distant  place ;  but  it  often  hap. 
pens  also  that  the  water  nowhere  re-appears,  and  we  must  conclude  that  it 
runs  directly  into  the  sea.  All  these  circumstances  explain  the  disappear- 
ance  of  certain  rivers,  which  are  swallowed  by  the  earth  after  a  superficial 
course  of  more  or  less  extent,  as  well  as  the  sudden  appearance  of  springs 
gushing  from  the  side  of  a  rock.  They  point  to  the  existence  of  subterra- 
neous canals,  and  lead  us  to  think  that,  dried  up  by  a  more  or  less  consider- 
able upheaval,  these  canals  may  have  formed  the  now  empty  caverns  found 
at  all  heights,  as  well  as  those,  the  bottom  of  which  are  still  occupied  by  a 
stream  of  water  fed  from  lakes  or  rivers  on  the  surface. 

Still,  if  the  real  origin  of  most  of  these  subterraneous  cavities  be  not 
doubtful,  it  must  be  admitted  that  subsequently  important  changes  took  place 
in  the  general  form  and  condition  of  their  parietes ;  the  rounded  form,  wear 
and  polish  of  surfaces,  grooves,  different  excoriations,  and  in  all  positions, 
even  on  the  upper  part  of  the  vault,  an  erosive  action  of  which  water  alone 
is  incapable.  It  has  been  thought  this  liquid  might  have  been  charged  with 
carbonic  acid  gas,  which  is  frequently  disengaged  from  the  earth  through 
fissures  formed  in  it,  particularly  at  the  time  of  earthquakes,  and  that  the 
subsequent  effects  were  owing  to  its  dissolving  power. 


LESSON  IX. 

EXPLANATION  OF  VARIOUS  PHENOMENA  CONTINUED.  —  Deposits 
attributable  to  Volcanic  Action — Lava — Basa'lt — Action  of 
Basalt  on  Adjacent  Rocks — Dolomisation — Giants  Causeway 
— Tra'chytic  Formation — Trap  Rocks — Porphyry — Granitic 
Rocks — Injection  of  Granite — Metalliferous  Veins — Meta- 
mo'rphism — Effects  of  Erosion. 

I.  Volcanic  cones  and  lava  currents. — When  we  find  conical 
hilJs  isolated,  or  arranged  several  together  on  a  line,  and  covered 
with  scoriae,  sometimes  having  crate'riform  cavities  at 
the  summit,  surrounded  by  rapilli,  we  may  be  certain 
they  are  volcanic  cones,  however  ignorant  we  may  be 
of  the  epoch  of  their  activity.  If  on  mountain  sides, 
whatever  may  be  their  nature,  we  see  long,  straight 
masses.,  terminated  below  in  a  club,  hollow  in  the  mid- 
dle, and  thinning  out  above  in  a  pellicle  of  dislocated 
scoriae  (fig.  274),  their  origin  cannot  be  doubtful, 
although  every  other  trace  of  volcanic  action  may 
have  disappeared.  These  long,  straight  masses  are 
lava  currents.  If  we  find  these  matters  in  pebbles,  in 
Jf^  more  or  less  extensive  tables,  compact  below,  porous, 

'     cellular,  or  scoriaceous  above,  with  a  nearly  uniform 

1.  By  what  features  are  extinct  volcanoes  recognised  ? 


BASA'LTIC  DEPOSITS  OF  DIFFERENT  KINDS.         167 

surface,  we  may  conclude  they  were  accumulated  on  a  horizontal 
soil,  or  that  in  a  more  or  less  liquid  state  they  flowed  into  a  depres- 
sion. They  are  evidently  deposits  which  have  issued  from  the 
bosom  of  the  earth  in  a  state  of  fusion.  It  is  by  observations  of 
this  kind  we  are  enabled  to  recognise  extinct  volcanoes,  in  relation 
to  which  the  history  of  the  most  remote  times  is  entirely  mute. 

2.  Some  of  these  currents  resemble  what  is  called  basalt,  that 
is,  black  rocks  with  a  compact  base  of  la'bradorite,  containing 
black  pyroxene,  and  almost  always  magnetic  oxide  of  iron.   Very 
frequently  there  is  found  in  it  more  or  less  voluminous  nodules  of 
peridote,  and  sometimes  crystals  of  feldspar,  which  give  it  a  por- 
phyritic  structure.     These  currents  ordinarily  form  thick  deposits, 
frequently  divided   into   prismatic  columns,  sometimes   in   large 
irregular  pieces,  all  indicative  of  slow  cooling.    "The  palisades"  on 
the  North  River  are  examples  of  basa'ltic  columns. 

3.  Basa'ltic  deposits  of  different  kinds. — If  basa'lt  is  found 
in  well-ascertained  currents,  traceable  to  craters,  entirely  similar 
matter  is  found  in  very  different  positions.     There  is  a  great  deal 
of  it  that  forms  extensive  tables  of  considerable  thickness,  consti- 
tuting vast  plateaux ;  or  heaped-up  fragments  on  different  moun- 
tains, at  the  same  level,  the  heaps  corresponding,  and  seem  to  be- 
long one  to  the  other  like  parts  of  the  same  whole,  showing  a 
vast  dislocated  table.     Basa'lt  also  forms  isolated  masses,  hillocks 
in   the    midst   of    planes,   sometimes   very   distant    from   every 
other  formation  of  the  same  kind.    It  is  found  in  seams,  sometimes 
enclosed  in  the  soil  that  conceals  it,  sometimes  rising  here  and 
there  like  a  wall,  or  presenting  various  hillocks  on  the  same  line 
of  direction. 

All  these  dispositions  of  basa'ltic  deposits,  as  well  as  currents  or  streams, 
are  sometimes  found  together  in  the  same  country.  In  some  countries,  on 
the  contrary ,'there  is  no  trace  whatever  of  volcanic  cones  or  of  currents. 
In  all  cases,  however,  the  rock  possesses  the  general  characters  of  basa'it, 
and  seems  to  rest  indifferently  on  every  kind  of  formation,  even  on  vegeta- 
ble earth. 

4.  Tabular   basa'lt  brings    to 
mind  the  great  tables  of  Iceland, 
especially  those   of  the   eruption 
of    1783 ;    they    possess   all   the 
characters  of  lava  that  has  been 
arrested  on  horizontal  planes,  or 
filled  depressions.   The  lower  part 
is  compact,  crystalline,  and  most 
frequently    divided    into    vertical 
prismatic    columns    (fig-    275) ; 

and  the  upper  part  is  porous,  eel-  Figt  w&.—Ifebtvm  <tf  priimatie 
lular,   sco'riform,    irregularly   di-  porous  basa'lt. 

2.  What  is  basa'lt  ?     What  does  it  contain  ?     What  is  its  form  ? 

3.  Where  is  basa'lt  found,  and  under  what  circumstances  ? 


168  BASA'LTIC  HILLOCKS,  OR  BOSSES. 

vided,  and  terminating  on  a  plain  horizontal  surface.  When  the 
mass  is  composed  of  several  stories,  the  separations  are  sometimes 
formed  by  thin  beds  of  rapilli,  and  most  generally  they  are  dis- 
tinguished by  alternations  of  compact  and  porous  matter,  which 
characterizes  each  particular  effusion. 

5.  These  characters  leave  no  doubt  as  to  the  igneous  origin  of 
these  deposits ;  but  there  are  still  others.   When  we  can  penetrate 

beneath  basa'ltic  tables,  as  in  cases 
where  they  rest  on  moveable  forma- 
tions, we  almost  always  find  the  in- 
ferior part  of  the  mass  presents  a 
multitude  of  appendages  (fig.  276), 
which  penetrate  into  the  soil,  indi- 
cating a  liquid  matter  that  has  been 
moulded  in  rents  or  crevices.  The 
earth  on  which  the  mass  rests  is 
often  found  calcined  through  a  great- 
er or  less  thickness,  and  the  debris 
Fig.  276. — Appendages  of  basa'lt  of  plants  it  contains  are  carbonised. 
in  subjacent  rocks.  On  the  other  hand,  there  is  often 

found  on  the  surface  of  basa'ltic  tables  points  of  scorification,  par- 
ticular elevations,  and  even  crate'riform  depressions,  towards  which 
the  melted  matter  seems  to  have  retired  at  a  certain  moment  before 
solidifying. 

6.  Basa'ltic  hillocks,  or  bosses,  are  of  different  kinds ;  some 
seem  to  be  the  remnants  of  an  extensive  table  which  had  been 
partly  destroyed  ;  in  this  case  the  principal  mass  of  the  bosse  be- 
longs to  one  or  another  species  of  soil,  and  the  summit  only  is 
basa'ltic.     In  others,  on  the  contrary,  the  whole  hillock  is  formed 
of  basa'lt,  and  the  base  is  lost  in  masses  of  sand  and  debris,  which 
prevent  us  from  seeing  what  is  beneath ;  some  others  are  attached 
to  veins  or  seams.     The  composition  of  these  hillocks,  like  that  of 
tabular  basalt,  varies. 

7.  Basa'llic  veins,  or  seams.     Basa'lt  is  frequently  found  in 
veins.     Most  frequently  the  mass  of  the  seam  or  vein  is  compact, 
or  irregularly  cracked,  but  it  is  often  divided  into  prisms,  perpen- 
dicular to  the  parietes  of  the  crevice,  which  then  become  the 
cooling  surfaces  (fig.  277).   The  matters  in  these  seams  are  rarely 
scorified,  but  some  instances  are  met  in  Vivarais  and  Auvergne. 
Most  frequently  basa'ltic  veins  are  prolonged  to  the  surface  of  the 
soil,  where  they  present  their  out-crop  ;  but  it  frequently  happens, 
also,  they  terminate  above  in  pointed  masses  (fig.  278),  sometimes 
bifurcated,  which  are  lost  in  the  rocks  through  which  they  pass. 

4.  What  are  the  characters  of  tabular  basa'lt  ? 

5.  What  is  the  origin  of  basa'lt  ? 

6.  What  are  the  characters  of  bosses  of  basa'lt  ? 

7.  What  are  the  characters  of  basa'ltic  veins  ? 


BASA'LTIC  HILLOCKS,  OR  BOSSES. 


169 


277.  —  View   of  prismatic  Fig.  278.  —  Basaltic  seams  of 

basa'lt.  Villeneuve-de-Berg. 

This  circumstance  positively  indicates  that  the  basa'lt  was  not  in- 
troduced from  above,  and  that  it  could  only  have  been  injected 
from  the  interior  towards  the  exterior  of  the  earth.  Sometimes 
the  vein  glides  betwixt  two  strata,  which  it  follows  to  a  greater  or 
less  extent ;  or,  in  ramifying,  it  launches  a  part  of  its  mass  into 
the  interval,  and  ends  by  terminating  there  in  a  corner,  whence  it 
spreads  into  all  the  little  fissures  of  the  rock. 

8.  Along  the  course  of  basa'ltic 
veins,  the  out-crops  of  which  are 
seen  on  the  surface  of  the  soil, 
various  isolated  hillocks  are  fre- 
quently observed  (fig.  279),  seve- 
ral together  at  various  distances 
apart,  which  appear  to  be  nothing 
more  than  partial  ejections,  like 
the  cones  formed  along  the  same 
crack  in  modern  volcanic  erup- 
tions.  Most  often  they  are  almost 

entirely  composed  of  scoriae,  but  Fig.  27 '9. —Hillocks  on  the  course  of 

some  are  found  which  consist  of  a  vein. 

pure  basa'lt.     Sometimes,  instead  of  hillocks,  there  are  effusions 

of  tables  of  more  or  less  thickness  (Jig.  280),  which  are  also 

found   along  the   course  of  a 

vein.     All  these  circumstances 

tend   to  explain    the  formation 

of  isolated  hillocks,  as  well  as 

the   series  of  hillocks  in  line,  Fi?'  280.-F«»  terminating  in  «  table. 

found  in  a  great  many  localities  where  the  internal  vein  has  found 

here  and  there  an  outlet. 

9.  diction  of  basa'lt  on  adjacent  rocks. — The  calcination  of 
clays,  and  the  carbonisation  of  vegetable  debris  lying  beneath  ba- 
sa'lt, have  been  mentioned  ;  granite  traversed  by  veins  of  it  is  very 
much  altered,  portions  of  rocks  which  have  been  enveloped  in 

8.  Mow  are  isolated  hillocks  of  basa'lt  accounted  for  ? 

IS 


170 


ACTION  OF  BASA'LT  ON  ADJACENT  ROCKS. 


basa'lt  are  often  melted  on  the  surface,  quartz  and  feldspar  are 
cracked,  sometimes  enveloped  or  penetrated  by  vitreous  matter. 
Marls,  earthy  limestones  in  contact  with  basa'lt,  or  pierced  by  its 
veins,  and  especially  fragments  of  matter  drawn  into  the  basa'ltic 
mass,  are  converted  into  compact  limestone,  sometimes  approach- 
ing the  saccharo'id  state.  These  limestones  also  become  magne- 
sian,  and  are  converted  into  true  dolomites,  distinguished  from  the 
rest  of  the  enveloping  mass  by  their  slow  effervescence.  Dolomi- 
sa'tion  seems  to  be  due  to  the  presence  of  igneous  products.  When 
basa'ltic  veins  pass  through  carbona'ceous  deposits,  the  clays  are 
calcined,  the  coal  is  deprived  of  its  bitu'men,  and  assumes  a  baccil- 
lar  (berry-like)  structure. 

Basa'ltic  deposits,  in  tables,  hillocks,  or  veins,  are  more  abundant  on  the 
surface  of  the  globe  than  all  the  lavas  in  ascertained  currents,  which  is, 
doubtlessly,  owing  to  their  mode  of  ejection.  Basa'lts  are  found  in  France, 
on  the  borders  of  the  Rhine,  in  Saxony,  Bohemia,  &c.  Iceland  contains  a 
great  quantity,  and  the  same  rocks  predominate  in  the  West  Indies,  at  St. 
Helena,  &c.,  and  in  almost  all  the  islands  of  the  South  Seas. 

Basa'ltic  formations  are  noticed  wherever  they  occur,  in  consequence  of 
the  tendency  of  the  principal  rocks  to  divide  into  long  prisms,  the  varied 
arrangements  of  which  have  often  excited  the  admiration  of  the  curious. 
Here  all  the  prisms  converge  at  the  summit  of  a  hillock ;  there  they  form 
magnificent  colonnades  of  the  most  picturesque  appearance;  in  another 
place  all  the  columns,  broken  at  the  same  level,  present  a  pavement  com- 
posed of  pieces  regularly  joined,  extending  over  a  greater  or  less  space,  and 
sometimes  formed  into  an  amphitheatre,  one  above  the  other.  The  gran- 
deur,  the  imposing  appearance  of  these  pavements,  have  obtained  for  them 
the  name  of  Giants1  Causeway. 

The  Giants'  Causeway  in  Ireland  is  famous ;  but  a  similar  structure 
exists  in  France.  Sometimes  there  are  excavations  in  the  middle  of  ba- 
sa'ltic masses,  or  trappean  rocks,  which  resemble  them  most,  some  of  them 
forming  very  remarkable  grottoes.  The  most  celebrated  is  Fingal's  cave, 

in  the  island  of  Staffa, 
which  is  formed  in  the 
midst  of  trap,  divided 
into  prismatic  columns 
with  the  utmost  regu- 
larity, and  into  which 
the  sea  continually  beats. 
Others  exist  in  the  ba- 
sa'lt, properly  so  called  ; 
there  is  a  famous  one 
on  the  banks  of  the 
Rhine,  between  Troves 
"  and  Coblcntz,  near  Ber- 
trich-Baden  (Jig.  281), 
the  columns  of  which 
are  composed  of  rounded 
pieces,  which  has  caused 
Fig.  281.7—  Cheese-grotto,  at  Bertrich-Baden.  tnem  to  be  compared  to 
piles  of  cheeses,  whence  the  name  of  cheese-grotto,  common  in  the  country. 

9.  What  influence  does  basa'lt  exert  over  adjacent  rocks  ?  What  is 
meant  by  dolomisation  ?  Give  some  instances  of  basa'ltic  formation, 


TRACHYTIC  FORMATION.  171 

10.  The  Tra'chytic  formation  is  very  extensive.     It  presents 
itself  not  only  in  conical  hillocks,  running  in  narrow  bands,  but 
also  in  pi led-up  tables  on  the  surface;  tra'chyte  constitutes  great 
mountains,  most  frequently  united  in  very  extended  groups,  which 
form  very  high  masses,   ordinarily  the  highest  in  the  country, 
covered  with  asperities  ;  their  sides  are  broken  into  valleys  and 
deep  ravines,  with  steep  escarpments,  and  with  all  the  circum- 
stances of  lofty  chains.      The  tra'chytic  formation  is  in   strong 
contrast  with  the  igneous  rocks  we  have  heretofore  studied,  al- 
though close  inspection  would  show  them  to  bear  various  relations 
with  deposits  of  basa'lt  or  lava. 

11.  The  rocks  which  constitute  the  tra'chytic  formation  are  ex- 
tremely varied.    Most  of  these  substances,  as  their  name  indicates, 
are  rough  to  the  touch,  because  they  are  most  generally  finely 
porous,  sometimes  cavernous,  scoria'ceous,  pumice-like  ;  but  there 
are  some  that  are  perfectly  compact,  and  present  the  porphyri'tic 
structure,  frequently  with  tints  of  grey,  red,  brown,  or  black,  on 
which  are  white  crystals  of  albi'te  and  of  rya'colite.     There  are 
some,  more  or  less  earthy,  ordinarily  of  clear  tints,  called  domi'te, 
because  the  Puy  de  Dome  is  composed  of  it.     The  base  of  all 
these  rocks,  which  is  inattackable  by  acids,  is  albi'tic  or  ryacoli'tic, 
formed  of  a  multitude  of  microscopic  crystals  mingled  together, 
the  whole  constituting  a  mass  which  is  more  or  less  compact.    The 
disseminated  substances  are  albi'te,  in  crystals  of  greater  or  less 
size,  rya'colite,  black  mica,  amphibole  hornblende,  but  rarely  py'- 
roxene  augi'te.    Gluartz  in  crystals-,  and  chalcedony  in  small  nodules 
are  also  found  in  it  sometimes,  and  especially  in  a  certain  very 
cavernous  species,  hitherto  found  only  in  Hungary,  the  cement  of 
which  also  contains  many  small  striated  balls  of  sphe'rolite  (from 
the  Greek  spheira,  a  sphere,  and  lithas,  a  stone). 

12.  The  name  pho'nolite  (from  the  Greek  photic,  a  sound,  and 
lithos,  a  stone)  has  been  given  to  rocks  more  or  less  analogous  to 
tra'chyte,  but  differing  from  it  in  this,  that  their  base  is  attackable 
by  acids,  leaving  a  residue  of  rya'colite.     These  rocks  are  most 
often  compact,  greyish  or  greenish,  sometimes  porphyroid,  but  in 
which  disseminated  substances  are  rare.      They  are  frequently 
divided  into  plates  or  leaves  of  variable  thickness,  and  in  certain 
cases  the  whole  mass  is  divided  into  prismatic  columns,  which  are 
more  frequently  divergent  and  contorted  than  vertical.     Pho'no- 
lites  have  been  sometimes  confounded  with  certain  porphyroidal 
varieties  of  tra'chyte,  which  possess  nearly  the  same  appearance, 
but  not  the  same  solubility. 

13.  Some  tra'chytic  formations  contain  considerable  deposits  of 

10.  Under  what  forms  do  we  find  the  tra'chytic  formation  ? 

11.  What  are  the  characters  of  those  rocks  which  constitute  the  tra'- 
chytic formation  ?     What  is  domite  ? 

12.  What  is  phonolite  ?     What  are  its  characters  ? 
33.  Do  all  tra'chytic  formations  contain  obsidian  ? 


172  DIORITE,  TRAP  ROCKS,  &c. 

obsidian  and  of  pe'rlite,  with  ail  their  gradations  to  pumice.  Their 
abundance  and  character  vary  according  to  locality ;  they  prepon- 
derate in  some  countries,  while  in  others  scarce  a  trace  of  them  is 
to  be  seen. 

14.  Di'orite,  trap  rocks,  amyg'dalo'id,  fyc. — There  is  nothing 
more  analogous  to  basa'lt  than  certain  black  rocks,  some  of  which, 
according  to  the  numerous  gradations  they  present  in  deposits  in 
which  the  elements  are  distinct,  must  be  mixtures  of  albi'te  and  of 
amphibole,  and  others  are  of  an  unknown,  or  at  least  doubtful 
nature.     The  first  are  designated  in  France  under  the  name  of 
di'orite,  and  in  Germany  they  are  known  as  grunstein.     The 
others  have  long  borne  the  appellation  of  trap  (from  the  Swedish, 
trappa,  a  stair),  the  nature  of  w^hich  it  is  still  impossible  to  deter- 
mine definitely.     These  rocks  bear  some  relation,  as  much  by 
their  position  in  certain  localities  as  by  their  mineralogical  charac- 
ter, to  certain  substances  called  amy^dalo'ids,  in  consequence  of 
the  nodules  of  various  matters  they  contain,  which  are  known  in 
England  as  loadstone,  and  whinstone,  the  nature  of  which  is  often 
not  better  known. 

15.  For  a  long  time  these  rocks  were  supposed  to  be  of  aqueous 
origin  ;   but  it  is   now  ascertained   that  they  are  from   igneous 
causes. 

16.  At  first,  in  spite  of  the  absence  of  scoria'ceous  matters, 
these  rocks,  and  especially  those   named  trap,   present  all  the 
features  of  basaltic  deposits ;  they  are  found  in  isolated  hillocks, 
or  in  tables  of  greater  or  less  extent ;  their  mass  is  often  divided 
into  prismatic  columns,  which  possess  precisely  the  same  appear- 
ance as  basaltic  colonnades,  giants'  causeways,  and  all  the  forms 
of  basa'lt.     On  the  other  hand,  these  substances  are  frequently 
found  in  veins ;  and  it  is  remarked  that  these  veins  or  seams  ter- 
minate above   in   a   pointed   mass 
(a,  Jig.  282),  or  in  their  course  send 
off  small  ramifications  (6)  into  the 
rocks  through  which  they  pass — 
small  masses  (c),  sometimes  isolated, 
sometimes  communicating  with  the 
principal  mass  by  a  thin  seam.  The 
enclosing  rocks  are  sometimes  occa- 

Fig.282.-Veins  of  trap -Iceland.  siona]]y  perforated  by  small  ramifi- 
cations, and  even  to  the  finest  fissures.  These  circumstances  evi- 
dently show  these  are  not  cracks  filled  from  above,  and  can  be 
regarded  only  as  injections  from  the  interior,  thrown  with  sufficient 
force  to  penetrate  the  smallest  fissures,  to  detach  and  carry  away 
fragments  of  rock  sometimes  found  in  their  substance,  as  at  d. 

17.  All  these  circumstances  are  exactly  the  same  as  those  seen 

14.  What  is  di'orite  ?     What  is  trap  ? 

15.  What  is  the  origin  of  di'orite  and  trap  ? 

16.  What  are  the  characters  of  trap  ?     In  what  form  is  trap  met  with  ? 


SERPENTINE— PORPHYRIES.  173 

in  basa'lt.  It  is  the  same  with  beds,  in  appearance  regular, 
seen  between  sedimentary  layers  ;  observation  shows  they  are 
only  ramifications  of  veins.  This  is  clearly  seen  at  Trotternish, 
in  the  isle  of  Sky  (Jig.  283),  where  a  great  seam  of  trap  commu- 
nicates with  a  bed  of  similar  matter,  which  is  itself  divided  further 
on  into  three  branches.  Hence  it  is  evident  the  intercalation  of 


Fig,  283. — Injection  of  trap  into  sedimentary  rocks.   Isle  of  Sky.  . 

tra'ppean  rocks  in  arena'ceous  beds  is  the  result  of  an  injection, 
which  followed  the  separation  of  the  beds  of  the  sedimentary  de- 
posit to  a  greater  or  less  distance,  as  in  the  case  of  the  basa'lts  of 
Villeneuve-de-Berg  (fig.  278). 

18.  Ser'pentine  and  Didllage  ;  different  porphyries. — Magne- 
sian  rocks,  called  ser'pentine,  often  accompany  trap  and  di'orite ; 
they  very  frequently  form  seams  or  veins  of  themselves.  Ser'- 
pentines  and  eu'photides  are  often  injected  in  all  manners  into  cal- 
careous deposits  belonging  to  the  jura'ssic  period.  Sometimes 
they  form  veins,  sometimes  thick  strata ;  they  often  present  brec- 
cias of  every  species  which  constitute  the  marbles  called  verd 
anti'que,  verd  d* Egypte,  &c.  The  limestones  mingled  with  these 
rocks  are  all  in  the  saccharoid  state,  and  furnish  the  most  beautiful 
statuary  marble  and  the  most  brilliant  breccias;  yet,  if  we  ex- 
amine them  carefully,  we  find  they  belong  entirely  to  the  compact, 
and  more  or  less  earthy  limestones,  the  surrounding  deposits  of 
which  they  are  evidently  a  continuation.  The  schistose  clays  and 
sandstone,  which  alternate  with  the  last,  are  found  converted  in 
the  others  into  jaspers  of  different  varieties. 

The  appearance  of  pyroxenic  rocks,  mela'phyries  (porphyries,  the  con- 
stituents of  which  are  united  by  a  black  cement),  and  other  porphyries 
which  belong  to  them,  is  productive  of  circumstances  of  the  same  kind ; 
M.  de  Buch  long  since  pointed  them  out  in  the  Tyrol,  and  subsequently  in 
upper  Lombardy.  They  are  also  found  all  along  the  Alps,  arid  are  repre- 
sented in  the  same  direction  in  Provence  in  the  midst  of  the  mountains  of 
Esterel :  all  is  upturned  in  the  neighbourhood  of  these  rocks,  which,  in 
"  coming  to  day,"  have  upheaved  around  them  calcareous  deposits  of  dif- 
ferent formations,  dislocating,  and  placing  them  in  the  most  abnormal  posi- 
tions. Wherever  they  are  in  contact  with  these  porphyries,  and  to  a  con- 
siderable distance  beyond,  limestones  are  transformed  into  dolomite,  and  in 
such  a  manner  that  the  same  deposits  are  of  simple  limestone  in  some  part?, 
and  of  dolomite  injected  into  those  which  are  near  to  rocks  of  crystalliza- 
tion. What  is  most  remarkable  is,  that  the  few  organic  remains  met  in 

17.  How  does  trap  resemble  basa'lt  1 

18.  What  is  serpentine  1   What  is  verd  antique  1 

15* 


174 


GRANITIC  ROCKS. 


these  modified  limestones,  even  the  shells  of  rnollusks  or  madrepores,  are 
found  changed  into  magnesia ;  this  clearly  proves  that  an  action  subsequent 
to  the  formation  of  the  deposit  has  produced  dolomisa'tion,  for  no  shell  or 
madrepore  exists  which  naturally  contains  magnesia,  either  in  the  living  or 
fossil  state,  where  the  deposit  has  undergone  no  modification. 

Feldspathic  porphyries  are  often  so  characterized  that  there  can  be  no 
doubt  of  their  igneous  origin.  Not  only  are  they  found  in  veins  in  the 
midst  of  rocks,  but  they  act  like  trachytes,  in  passing  through  split 
rocks,  the  fragments  of  which  they  glue  together  to  form  conglomerates  ; 
they  often  unite  themselves  in  the  most  intimate  manner  to  arena'ceous  de- 
posits which  harden  in  their  vicinity. 

19.  Granitic  rocks. — There  can  be  no  doubt  as  to  the  igneous 
nature  of  the  preceding  rocks,  from  the  manner  in  which  they  are 
injected  into  all  kinds  of  deposits,  and  from  the  modifications  they 
produce  in  the  substances  they  pass  through  or  upheave.     The 
same  is  true  of  all  granitic  rocks,  that  is  of  granite  properly  so 
called,  of  syenites,  which  resemble  them  more  or  less  in  appear- 
ance, and  pass  into  them  in  all  manners,  of  certain  gneiss  rocks, 
which  belong  immediately  to  one  or  the  other,  &c.     In  short,  it  is 
inferred  from  a  great  mass  of  observations,  collected  first  in  Eng- 
land by  Dr.  Macculloch,  afterwards  verified  by  other  geologists, 
that  the  granites,  which  are  massive  rocks,  and  therefore  distinct 
from  aqueous  deposits,  which  are  ordinarily  stratified,  act,  on  their 
appearance,  exactly  like  the  traps,  diorites,  and  porphyries. 

20.  In  the  valley  of  Glen-Tilt,  in  Scotland,  granite  is  found 
injected  into  calcareous  deposits,  which  alternate  with  argilla'ceous 
schists  (Jig>  284),  into  which  it  sometimes  forces  separate  masses 
(«) ;  fragments  of  limestone  (6)  are  also  found  enveloped  in  the 
granite  itself.     In  other  places  vertical  veins  traverse  the  rock 
(Jig>  285),  sometimes  entirely,  sometimes  terminating  in  pointed 


Fig.  284 


Fig.  285. 


Injection  of  granite  into  different  rocks. 


19.  What  is  the  origin   of  granitic  rocks?     What  rocks  are  included 
under  the  name  of  granitic  rocks  ? 
'  20.  What  circumstances  prove  the  igneous  origin  of  granitic  rocks  ? 


METALLIFEROUS  LODES,  VEINS,  MASSES.  173 

masses,  like  the  dio rites  and  basa'lts,  which  also  shows  that  the 
matter  came  from  below  upwards,  and  that  it  was  driven  with 
great  force.  These  facts  do  not  present  themselves  in  a  particular 
locality  only,  but  are  observed  in  all  parts  of  the  world. 

The  state  of  pasty  fusion  in  which  the  granites  were,  is  indicated  by  the 
manner  in  which  these  rocks  are  enveloped  in  certain  sedimentary  deposits, 
or  effused  on  the  different  soils  they  pass  through.  In  the  coal-measures 
of  La  Pleau,  to  the  south-west  of  Ussel,  a  portion  of  the  formation  has  been 
enveloped  by  porphyroid  granites,  which  are  found  above  and  below.  '  The 
coal  is  there  hard,  as  on  all  the  plateau,  and  the  deposit  is  very  irregular. 
In  a  great  many  localities,  we  find  granite  superposed  on  all  sedimentary 
deposits  from  schists,  and  the  most  ancient  rocks,  to  those  of  the  jura'ssic 
period.  There  are  different  places  in  the  Alps,  where  one  may  touch  at  the 
same  time,  superposed  rocks  of  crystallization  and  the  subjacent  sedimentary 
deposit. 

The  action  of  granitic  rocks  on  those  through  which  they  pass  is  the 
same  as  that  of  the  preceding  rocks  ;  compact,  o'olitic,  and  earthy  lime- 
stones are  converted  into  saccharoid  limestones,  from  which  organic  re- 
mains have  most  frequently  disappeared ;  they  assume  bright  colours  of 
every  kind,  green,  red,  black,  &c.,  and,  in  contact  with  mica,  are  filled  with 
garnets  and  various  other  crystalline  substances.  They  are  often  converted 
into  dolomites,  which  are  nowhere  more  abundant  than  in  formations  of 
granite — and  sometimes  into  gypsum,  as  proved  by  the  out-croppings  of  this 
substance  in  certain  parts  of  the  Alps.  Clays,  and  various  arena'ceous  sub- 
stances are  transformed  into  jasper,  and  finally  assume  the  characters  of 
mica'ceous  or  talcose  schist,  and  gneiss.  Simple  sandstones  of  sedimentary 
formations,  on  the  approach  of  granite,  are  converted  into  beds  of  granular 
quartz.  It  sometimes  happens  that  modified  schistose  sandstones  still  pre- 
serve their  arena'ceous  structure,  although  they  may  have  become  very 
solid  ;  even  the  mica-schists  to  which  they  pass  contain  here  and  there  thin 
strata  of  sandy  quartz,  interposed  between  laminae  of  mica,  which  seems  to 
announce  the  remains  of  ancient  modified  sandstone. 

Granitic  rocks,  referred  to  different  ages,  are  very  abundant  on  the  sur- 
face of  the  globe  ;  being  found  sometimes  in  very  lofty  mountain  chains, 
and  sometimes  forming  rounded  hills  disintegrated  on  the  surface,  and  cover- 
ing considerable  extents  of  country. 

21.  Metalliferous  lodes,  veins,  masses. — The  dolomisa'tion 
and  the  sulphatisa'tion  of  limestones,  the  presence  of  various  sub- 
stances in  adjacent  rocks,  are  not  the  only  facts  referable  to  the 
passage  of  igneous  rocks  from  the  bosom  of  the  earth.  It  also 
happens  that,  on  the  contact  of  the  new  with  the  ancient  rock,  the 
deposits  are  filled  with  different  metallic  minerals,  either  dissemi- 
nated or  injected  into  fissures,  and  between  beds,  or  accumulated 
in  small  masses,  sometimes  united  by  slender  threads.  This  has 
been  remarked  by  M.  Dufrenoy  in  regard  to  iron  ores  in  the  Py- 
renees, which  are  found  either  in  limestone,  or  placed  between 
sedimentary  deposits  and  the  granite  which  upheaved  the  solid 
mass. 

It  is  evident,  lodes  or  seams  of  ores  are  related  to  igneous  action.  As  to 
those  which  are  deposited  in  veins,  it  is  to  be  remarked,  we  have  never  had 
occasion  to  follow  them  to  a  sufficient  depth  to  ascertain  whether  they  ter- 

21.  How  are  metalli'ferous  veins  produced  ? 


176  METALLIFEROUS  LODES,  VEINS,  MASSES. 

minate  abruptly,  and  consequently  whether  they  fill  cracks  opened  from  the 
surface  towards  the  interior ;  but  they  are  known  to  terminate  in  pointed 
masses  upwards,  as  at  Joachimstal  in  Bohemia,  and  in  many  other  places, 
in  small  veins  which  have  been  worked.  This  circumstance  leads  us  to 
think  that  metalli'ferous  veins  have  been  produced  by  an  injection  from  the 
interior  towards  the  surface,  in  the  same  way  as  the  stony  veins  we  have 
mentioned.  Besides,  veins  of  this  sort  are  strongly  united  to  the  others : 
thus,  at  Pontgibaud,  the  same  veins  are  sometimes  granitic  and  sometimes 
metalli'ferous ;  in  many  other  places  metalli'ferous  veins  accompany  por- 
phyritic  veins,  and  even  veins  of  basa'lt,  as  in  Bohemia,  and  the  two  sub- 
stances mutually  penetrate  each  other,  sometimes  one  and  sometimes  the 
other  being  above.  On  the  other  hand,  we  very  frequently  find  in  the  same 
localities  stony  and  metalli'ferous  veins  running  parallel  to  each  other, 
sometimes  crossing  in  different  ways,  one  throwing  the  other  aside,  and 
thus  mutually  producing  more  or  less  marked  faults.  Sometimes  the  stony 
displace  the  metalli'ferous  veins ;  sometimes,  on  the  contrary,  the  latter 
turn  aside  the  others :  in  everything  they  act  exactly  alike,  and  it  is  impos- 
sible not  to  refer  them  to  the  same  origin.  It  is  also  remarked  that  veins 
generally  follow  great  lines  of  dislocation  of  the  crust  of  the  earth. 

We  find  in  metalli'ferous  veins  the  influence  of  those  which  pass  through 
or  accompany  them,  and  which  deposit,  to  a  certain  extent,  substances  not 
previously  observed.  The  influence  of  the  rock  passed  through  is  seen  in 
metalli'ferous  veins,  as  well  as  in  those  of  trap;  and  it  has  been  long  known  to 
miners,  that  a  poor  vein  in  a  determined  bed  at  once  becomes  rich  by  pass- 
ing into  another,  and  the  contrary  :  hence,  the  sudden  success  and  unfore- 
seen reverses  in  mining  operations. 

22.  Metalli'ferous  masses  being  in 
general  but  accumulations  of  small  veins 
running  in  all  directions  (fig.  286),  or 
an  abundant  dissemination  in  the  midst 

of  a  stony  substance  of  the  kind  attri- 
Metalli'ferous     bute(J    to   t^e   action   of  flre>   ^   js   clear 

these  deposits  are  produced  in  the  same 

way  as  those  just  mentioned.  These  masses,  the  principal  of 
which  present  us  with  ores  of  tin,  copper  py'rite's,  and  magnetic 
iron,  are  chiefly  composed  of  granites,  porphyries,  various  mag- 
nesian  rocks,  in  which  the  ores  are  found.  The  metalli'ferous 
mass  of  Zinwald,  in  Bohemia,  is  a  particular  granite  enclosed  in 
a  porphyry;  that  of  Altemberg,  in  Saxony,  is  a '  porphyritic  mass 
enclosed  in  gneiss.  The  celebrated  mass  of  magnetic  iron  of 
Taberg,  in  Sweden,  is  a  mass  of  diorite  enclosed  in  gneiss  ;  that 
of  Cogne,  in  Piedmont,  is  a  mass  of  serpentine  driven  into  the 
calci'ferous  mica'ceous  schist. 

23.  Metalli'ferous  lodes  in  regular  beds,  are  merely  veins  which 
have  followed  the  stratification,  as  we  observed  in  traps  (fig.  283), 
or  deposits  which  were  formed  in  contact  with  sedimentary  beas 
and  the  fused  matters  that  upheaved  them.  But  we  must  not  con- 
found the  masses  and  veins,  just  mentioned,  with  certain  deposits 
of  o'olitic  iron  ores  found  in  sedimentary  formations.  Among  the 

22.  Of  what  do  metalli'ferous  masses  usually  consist  ? 

23.  What  is  meant  by  the  term  lode  ? 


METAMORPHISM.  177 


latter,  some  form  beds  of  more  or  less 
extent  in  the  midst  of  calcareous  forma- 
tions, others  fill  wide  apertures  of  little 
depth,    from    above,   which    sometimes 
communicate   with   caverns   (fig  287) ;  p.     287.-. 
but  these  facts  are  of  a  different  order          from  t]le  exterior. 
from  those  just  described. 

24.  Metamorphism. — From  all  the  facts  we  have  cited  (which 
might  be  vastly  augmented  in  number  by  reference  to  details  in 
many  localities),  we  must  conclude  that  crystalline  rocks,  which 
are  all  formed  of  si'licates,  extensively  varied  and  mixed  with  each 
other,  have  been  produced  by  the  action  of  fire ;  that  at  different 
epochs  they  have  dislocated,  uplifted,  or  overturned  the  sediment- 
ary deposits,  modifying  the  mass  in  all  manners — and  it  is  to  these 
great  phenomena  that  are  due  all  the  seeming  disorder  observed 
on  the  surface  of  the  globe,  as  well  as  all  the  successive  changes, 
the  traces  of  which  may  be  perceived  at  every  step. 

When  we  see  earthy  or  compact  limestones  become  crystalline  on  the 
approach  of  these  different  kinds  of  rocks — to  fill  with  various  substances 
they  do  not  contain  at  certain  distances — to  be  charged  with  magnesia  in 
cracking  in  all  parts,  and  to  disintegrate  with  more  or  less  facility ;  when 
schistose  clays  and  arena'ceous  substances  are  converted  into  different 
jaspers,  and  become  charged  with  mica  and  am'phibole,  and  assume  the 
characters  of  gneiss,  of  mica'ceous  or  talcose  schist ;  finally,  when  sand- 
stones  are  transformed  into  beds  of  solid  quartz,  can  we  be  surprised  that 
most  modern  geologists  have  adopted  the  idea  of  complete  changes  effected 
in  a  great  number  of  sedimentary  deposits,  and  that  they  resort  to  this 
metamorphism,  long  since  perceived  by  Hutton,  Playfair,  and  Dr.  Macul- 
loch,  to  explain  a  multitude  of  facts,  observed  especially  in  deposits  anciently 
designated  under  the  names  of  primitive  and  transition  formations  ?  The 
facts  appear  so  extraordinary,  that  we  may  be  led  to  suppose  a  little  ex- 
aggeration :  but  we  must  reject  evidence  to  deny  that  there  are  saccharoid 
limestones,  dolomites,  mica-schists,  gneiss,  granular  quartz,  &c.,  which  are 
the  result  of  a  change  produced  in  earthy  or  compact  limestones,  clays, 
sands,  &c.  of  sedimentary  formation  :  is  it  then  so  ridiculous  to  suppose 
that  such  has  been  their  origin  in  all  cases? 

These  ideas,  now  more  striking,  because  they  are  expressed  by  a  proper 
word,  are  nevertheless  not  absolutely  new;  all  works  on  geology  are  actually 
full  of  them,  and  the  facts  are  not  less  remarkable  from  being  expressed  in 
other  terms.  There  is  no  description  of  a  country,  going  back  to  the  time 
of  Saussure,  whose  works  are  still  remarkable  for  their  fidelity  of  details, 
in  which  are  not  seen  numerous  passages  of  different  arena'ceous  deposits 
to  rocks  of  crystallization,  of  schistose  grauwackes  to  talcose  schists,  to 
mica'ceous  schists,  and  from  these  to  gneiss,  or  the  passage  of  sandstone  to 
different  kinds  of  granite  and  porphyries  on  which  they  rest,  &c.  Is  not 
the  fact  of  the  modifications,  now  described  under  the  term  of  metamor- 
phism,  here  clearly  indicated — to  which  time  has  added  only  more  details 
and  greater  precision  ? 

It  is  certain  that  in  departing  from  schistose  grauwackes,  for  example, 
and  going  towards  some  mountain  or  islet  of  crystallization,  we  find  these 

24.  What  is  meant  by  metamorphisrn  ?  Of  what  do  crystalline  rocks 
consist  ? 


17S  METAMORPHISM. 


substances  themselves  become  more  crystalline  in  character,  and  sometimes, 
without  losing1  the  organic  remains  they  contain,  become  filled  with  new 
minerals ;  in  Brittany  these  schists  are  filled  with  andalu'site,  sometimes 
staurotides,  near  all  granitic  deposits.  Elsewhere,  as  in  Vosges,  in  the 
mountains  of  Var,  we  see  them  pass  to  mica-schist ;  and  the  latter  to  gneiss, 
which,  itself,  insensibly  becomes  granite.  Now,  as  if  the  intimate  union 
observed  were  not  sufficient,  these  mica-shists,  then  the  gneiss  itself,  contain 
carburetted  schist,  or  even  graphite,  veins  of  anthracite,  which  remind  us  of 
the  deposits  which  are  found  further  in  the  schists  of  grauwackes,  and  suffi- 
ciently marked  to  determine  the  pursuit  of  coal. 

It  is,  then,  evident  that  all  the  rocks  we  have  cited,  no  matter  how  they 
may  differ,  are  only  modifications,  mere  metamorphoses  of  one  or  all ;  and, 
as  it  is  in  approaching  granitic  rocks,  evidently  produced  by  igneous  action, 
that  these  metamorphoses  become  more  and  more  marked,  jt  is  clear  that  it 
is  to  the  influence  of  the  latter  that  they  are  due.  The  same  influence  is 
manifest  on  the  sandstones  of  different  ages,  at  various  points  where  they 
are  in  immediate  contact  with  granite :  the  modifications  are  such  that  the 
special  name,  arkose,  has  been  applied  to  them.  They  then  pass  through 
all  shades  to  granite,  and  become  filled  with  different  substances  that  they 
do  not  contain  elsewhere. 

Near  porphyritic  ejections,  schists  frequently  present  modifications  of  an- 
other kind.  Here  the  most  earthy,  and  the  most  evidently  sedimentary  parts, 
pass  by  degrees  to  compact  substances,  more  and  more  fcldspathic,  preserv- 
ing more  or  less  of  their  schistose  character,  and  finally  end  by  containing 
crystals  of  feldspar ;  elsewhere  these  same  matters  pass  to  solid  clays,  con- 
taining veins  of  limestone,  then  nodules  of  the  same  substance,  which  as- 
sume all  the  characters  of  amygdaloids,  losing,  only  little  by  little,  their 
schistose  structure. 

The  same  phenomena  are  remarked  between  diverse  sandstones  and  por- 
phyries that  intersect  them.  The  arena'ceous  matter  gradually  hardens, 
becomes  more  compact,  and  finally  unites  with  the  porphyry  in  such  a 
manner  that  it  is  not  easy  to  determine  where  one  begins  or  the  other  ends. 

All  these  facts  pertain  really,  with  the  exception  of  some  details,  to  ancient 
geology ;  and  it  is  only  the  manner  of  explaining  them  that  has  changed. 
Everything  conspiring  to  demonstrate  that  crystalline  substances  have  been 
produced  by  the  action  of  fire,  and  forced  through  sedimentary  deposits,  we 
now  understand  that  the  latter  have  been  modified,  or  metamorphosed  in 
different  ways  by  their  influence,  in  a  degree  corresponding  to  their  proxi- 
mity :  the  effects  entirely  cease  only  at  greater  or  less  distances. 

It  is  conceived  that  one  part  of  these  metamorphoses  of  sedimentary  forma- 
tions  arises  from  the  simple  action  of  heat  without  new  fusion,  but  sufficient 
to  modify  the  texture  of  masses,  and  even  to  unite  elements  in  other  propor- 
tions, as  happens  when  transparent  glass  is  submitted  to  a  temperature  in. 
sufficient  to  melt  it,  in  which,  nevertheless,  a  new  crystallization  takes  place. 
But  this  idea  is  not  sufficient  of  itself;  we  must  conceive  another  action, 
which  we  are  not  yet  able  to  explain  or  account  for,  in  virtue  of  which  par- 
ticular substances  have  been  borne,  or  developed,  in  the  midst  of  rocks  found 
in  the  neighbourhood  of  divers  upturnings,  of  which  the  globe  is  the  theatre. 
We  readily  conceive  of  the  introduction  of  sulphuric  ac;d,  which  is  frequently 
formed  in  volcanoes ;  but  we  do  not  understand  that  of  magnesia  and  diffe- 
rent species  of  si'licates,  and,  as  respects  them,  all  is  still  purely  hypothetical. 
We  may  compare  these  facts  to  ctmenta'tion,  by  means  of  which  iron  is 
converted  into  steel ;  a  phenomenon  which  is  manifested  not  only  in  contact 
with  carbona'ceous  matter,  but  extends  far  into  the  ferru'ginous  mass,  and 
even  takes  place  at  a  distance,  according  to  the  experiments  of  M.  Laurent, 
who  has  shown  that  carbona'ceous  matter  may  penetrate  iron  even  through 


EFFECTS  ATTRIBUTABLE  TO  EROSION.  179 

porcelain  tubes.  We  also  know,  from  experiment,  and  many  effects  ob- 
served in  manufactories,  that  the  peroxide  of  iron,  the  oxides  of  chrome,  &c., 
are  vola'tilized,  and  penetrate  the  substance  of  bodies  that  envelope  them. 
The  experiments  of  M.  Gaudin,  with  a  blow-pipe  on  a  de'tonating  mixture, 
show  that  silex,  magnesia,  and  lime,  are  also  volatile  oxides ;  the  first  after 
fusion,  the  others  before  being  melted.  These  facts  evidently  lead  to  an  ex- 
planation of  all  the  phenomena  of  metamorphism,  arid  the  intrusion  of 
foreign  substances  into  sedimentary  deposits,  either  in  veins  or  in  a  state  of 
dissemination. 

EFFECTS    ATTRIBUTABLE    TO    EROSION. 

We  have  seen  that  waters  act  by  the  carbonic  acid  they  contain  ;  by  their 
Weight;  by  their  dissolving  power;  by  their  transporting  power;  by  their 
shock,  as  in  waves  of  the  sea,  and  thus  denude  continents.  We  have  also 
pointed  out,  that  in  arena' ceous  formations,  valleys  are  produced  by  erosion, 
precisely  as  ravines  are  formed  in  sandy  soils,  by  the  action  of  rain-water. 
Hence  we  may  infer  that,  in  every  revolution  that  movements  of  the  soil 
must  have  necessarily  determined,  the  waters,  thrown  forcibly  sometimes  on 
one  side  and  sometimes  on  the  other,  must,  as  in  our  time  during  earth- 
quakes, have  ravaged,  divided,  and  modified  pre-existing  deposits  in  various 
ways.  Many  circumstances  may  be  explained  by  erosion  of  waters,  and  the 
denudations  it  occasions. 

25.  At  first,  when  we  see  more  or  less  numerous  hillocks  of 
sedimentary  matter  in  a  country  (Jig.  288),  whose  summits  are 


Fig.  288. — Hills  produced  by  denudation. 

nearly  on  the  same  level,  and  whose  strata  correspond  with  each 
other,  we  are  naturally  led  to  consider  them  as  evidence  of  great 
removals  effected  by  the  waters,  at  certain  epochs,  the  relative 
dates  of  which  remain  to  be  ascertained.  In  this  way  we  explain, 
according  to  appearance,  all  the  sections  which  the  sandstones  pre- 
sent on  the  eastern  slope  of  Vosges ;  that  remarkable  assemblage 
of  peaks  of  every  form  seen  at  Aldersbach,  in  Bohemia ;  the  nu- 
merous hills  that  cover  Ross-shire,  in  Scotland  ;  the  gypseous  hills 
in  the  neighbourhood  of  Paris,  all  composed  of  the  same  beds 
placed  at  the  same  height ;  and  the  division  of  the  basa'ltic  tables 
that  crown  the  hills,  in  certain  localities,  as  well  as  the  rupture  of 
certain  lava-floods  that  had  barricaded  valleys,  &c.,  &c. 

Valleys  which  intersect  moveable  formations  are  evidently  produced  in  the 
same  way;  and  there  is  no  doubt  that  most  of  those  existing  in  solid  forma- 
tions, have  been  modified  by  erosion  of  water  after  the  rupture  which  gave 
origin  to  them.  In  this  way  we  may  explain  the  smoothing  of  all  their 
parietes,  in  a  great  many  localities,  and  the  widening  of  their  upper  parts. 
The  great  lakes  sometimes  found  at  the  extremity  of  valleys,  as  on  the  two 
slopes  of  the  Alp.-;,  in  Switzerland  and  Piedmont,  may  be  attributed  to  the 
afflux  of  waters  which  rushed  through  them,  at  the  period  of  some  great  ca- 
tastrophe, and  emptied  with  violence  on  the  plain  in  which  they  terminated. 

25.  What  forms  of  surface  are  attributable  to  erosion  and  denudation  ? 


180 


EFFECTS  ATTRIBUTABLE  TO  EROSION. 


Many  other  facts  are  explained  by  the  power  of  erosion  and  transport  by 
water.  When,  by  studying  faults  in  the  interior  of  mines,  we  clearly  see 
that  the  beds  no  longer  correspond,  and  that  a  part  of  the  formation  must 
have  been  uplifted  (Jig.  289) ;  then,  if  the  soil,  a,  i,  c,  is  level  on  the  surface, 


Fig.  289. 


Fig.  290. 


we  naturally  ask  what  has  become  of  the  beds  d  and  /,  which  ought  to  have 
formed  a  hillock  between  b  and  c.  It  is  clear  these  beds  must  have  been 
removed,  which  we  may  conceive  was  only  by  a  posterior  action  of  waters, 
which  carried  away  the  debris,  and  perhaps  spread  them  over  the  surface. 
In  the  same  way,  when  we  see  a  vein  form  a  projection,  a  dyke  on  the  sur- 
face of  the  soil  (Jig.  203,  page  119),  we  conceive  that  it  could  not  have 
formed  in  this  manner,  and  that  the  uncovered  part,  must  have  been  once 
encased  just  as  that  is  which  is  now  covered ;  the  surrounding  formation 
has  been  uplifted  then  afterwards,  at  least  along  the  whole  actual  height  of 
the  projection.  Something  similar  necessarily  took  place  at  points  where 
veins  crop  out  on  the  surface,  or  are  covered  by  moveable  soil  (fig.  290) ;  it 
is  not  probable  that  melted  matter  injected  in  the  crack  would  be  immedi- 
ately arrested  at  the  surface  of  the  earth,  and  it  is  presumable  that  the  soil 
has  been  removed  and  subsequently  covered  by  various  clearings.  We  are 
thus  led  to  understand  how  so  many  basa'ltic  masses  now  offer  no  trace  of 
scoria'ceous  matter,  neither  in  themselves  nor  in  their  vicinity.  These  im- 
perfectly aggregated  debris  have  been  subsequently  carried  away  by  the 
action  of  water,  and  perhaps  it  is  the  same  with  the  scoria'ceous  matter 
which  must  have  accompanied  the  appearance  of  trap. 

The  prodigious  power  exerted  by  waves,  and  the  effects  they  have  pro- 
duced in  our  times,  lead  us  to  think,  also,  that  all  the  rocks  formed  around 
islands  and  reefs  at  a  short  distance  from  coasts,  or  the  often  fanciful  groups 
in  the  midst  of  the  sea,  are  also  the  remnants  of  some  great  division  caused 
by  water,  as  much  in  removable  matters,  easily  disintegrated,  as  in  masses 
broken  by  earthquakes  and  different  movements  of  the  soil,  and  certain 
parts  of  which  have  been  afterwards  removed,  either  by  repeated  shocks  of 
waves  or  sudden  debacles.  In  this  way  we  may  explain  the  numerous 
accidents  in  rocks  which  bound  coasts,  or  are  isolated  in  the  midst  of  the 
ocean,  as  in  the  sinkings  of  the  chalk  of  Etretat  (fig.  291),  and  the  sec- 
tions of  porphyritic  or  granitic  rocks  in  the  Shetland  islands  (fig.  292).  It 
is  conceived  that  straits,  more  or  less  extended,  may  have  been  formed 
by  the  two  combined  actions  of  currents  of  water  and  rupture  which  the 
soil  might  have  undergone,  by  upheaval  or  subsidence,  at  determined 
epochs. 

From  these  observations,  we  see  that  many  effects  may  be  attributed  to 
the  action  of  water  which  cannot  be  in  any  other  way  explained.  We  may 
see  denudations  in  the  rnidst  of  mountains  and  valleys,  recognise  the  ancient 
sinkings  which  bordered  seas  at  different  ages,  and  hence  appreciate  their 
limits,  as  well  as  all  other  circumstances  connected  with  them.  Reference 
to  the  immediate  action  of  water  should  be  always  carefully  restricted  to  the 
moveable  or  loose  matters  found  on  the  surface  of  the  globe ;  for  when 
solid  matters  are  in  question,  which  water  attacks  too  slowly,  we  are  led  to 


CLASSIFICATION  OF  FORMATIONS. 


181 


Fig-.  291.  Fig.  292. 

Examples  of  rocks  cut  and  fashioned  by  water. 

think  that  currents  and  waves  cannot  act  effectively  until  the  soil  has  been 
previously  prepared  by  the  fissures  or  deteriorations  caused  in  rocks  by 
movements  of  the  earth. 

We  must  not  confound  with  divisions  produced  by  water  certain  accidents 
which  may  result  from  shrinking  produced  by  metamorphism.  This  pro- 
bably  takes  place  in  dolomites,  which  follow  compact  limestone  in  a  great 
many  places,  as  in  the  Tyrol  and  in  Cevennes.  Masses  of  these  matters 
are  frequently  split  and  slashed  in  all  directions  on  the  surface,  particularly 
on  the  summits  of  mountains  or  on  plateaux,  very  nearly  in  the  same  way 
that  calcareous  deposits  are  cut  by  water.  Now,  the  change  from  a  simple 
to  a  double  carbonate,  specifically  heavier,  requires  contraction  in  masses 
submitted  to  dolomisa'tion ;  therefore,  the  latter  must  be  split  and  cracked 
in  all  directions,  and  the  denudations  they  present  are  consequences  of 
these  effects. 


LESSON  X. 

Classification  of  Formations — Different  kinds  of  Stratification 
— Dip — Strike — Conformable  Stratification — Unconformable 
Stratification — False  Stratification — The  form  and  habits  of 
an  Minimal  deducible  from  a  single  bone — Relative  ages  of  the 
principal  catastrophes  of  the  Globe — Systems  of  Upheaval — 
Classification  of — State  of  Europe  at  different  epochs  of  forma- 
tion— Deluge—  Geogeny. 

Classification  of  Formations. 

1.  As  already  mentioned,  the  several  formations  are  divided  into 
two  ciasses,  namely : 

1st.  Massive,  or  igneous  formations,  which  are  produced  by  the 


1.  How  are  the  several  formations  divided  ? 
10 


What  are  the  divisions  ? 


182  CLASSIFICATION  OF  FORMATIONS. 

action  of  fire,  and  are  not  stratified.  The  terms  primitive  and 
transition  have  been  applied  to  these  formations,  but,  as  they  are 
inexact,  they  are  going  out  of  use. 

2d.  Sedimentary  formations,  which  are  deposited  by  the  action 
of  water,  and  are  stratified. 

2.  MASSIVE,  or  IGNEOUS  FORMATIONS  escaped  from  the  earth  in 
a  state  of  fusion,  and  became  solid  by  cooling,  but  without  being 
stratified.     They  are  divided  into  two  classes  :   1st,  those  crystal- 
line rocks  which  are  not  traceable  to  the  crater  of  any  volcano  now 
recognisable,  such  as  granite,  trachyte,  &c. ;  2d,  massive  rocks  of 
a  slightly  crystalline  structure,  traceable   to   volcanoes,  such  as 
modern  and  ancient  lavas,  and  basa'ltic  formations. 

3.  SEDIMENTARY  FORMATIONS  are  arranged  according  to  their 
relative  antiquity  :  they  are  divided  into  groups,  composed  of  those 
which  appear  to  have  been  formed  either  at  the  same  epoch  or 
during  a  geological  period,  during  which  the  general  condition  of 
the  earth  appears  to  have  undergone  no  important  change.    These 
formations  are  commonly  divided  into  five  groups,  namely: 

4.  First.   Primary  stratified  rocks,  in  which  neither  organic 
remains,  nor  fragments  of  the  most  ancient  rocks  are  found ;  this 
group  includes  gneiss,  mica-schist,  quartz,,  transition    limestone, 
and  argilla'ceous  schist. 

5.  Second.     The  transition  formations,  which  rest  on  the  pri- 
mary stratified  rocks,  and  contain  fossils  of  plants  or  animals,  but 
which  appear  to  have  been  deposited  prior  to  the  creation  of  the 
most  perfect  beings  of  either  kingdom,  and  only  contain  the  remains 
of  aquatic  animals,  which  are  all  very  different  from  those  of  our 
times,  such  as  tri'lobites  (fig.  4,  page  28).     This  group  includes 
fossili'ferous  schists,  transition  limestones,  &c. 

6.  Third.    The  secondary  formations  were  deposited  at  periods 
less  remote  than  the  transition,  and  consequently  rest  on  beds  of 
the  latter,  or  on  .primary  rocks ;  but  they  go  back  to  a  time  when 
the  state  of  the  globe  was  very  different  from  its  present  condition  ; 
very  few  mammals  then  existed ;  ammonites  are  among  the  most 
characteristic  fossils  of  the  secondary  formation  : 

The  secondary  formations  are  subdivided  into, 

1st.  The  carboniferous,  which  includes  old  red  sandstone,  mountain  lime- 
stone, and  coal : 

2d.  The  sali'ferous,  embracing  new  red  sandstone  muschelkalk,  and 
variegated  marls,  forming  the  tria'ssic  system  : 

2.  What  are  the  divisions  of  the  igneous  formations  ? 

3.  How  are  sedimentary  formations  arranged  ?     How  are  they  divided  ? 

4.  How  are  primary   stratified   rocks   characterized  ?     What  rocks  are 
included  in  this  group? 

5.  On  what  do  the  transition  formations  rest  ?     How  are  they  charac- 
terized ? 

6.  On  what  do  the  secondary  formations  rest  ?     What  are  the  most  cha- 
racteristic fossils  of  the  secondary  formations  ?     How  are  they  subdivided  ? 
What  are  the  divisions  ? 


MEANS  OF  DISTINGUISHING  FORMATIONS.  183 

3d.  The  jura'ssic,  embracing  the  lia'ssic,  the  o'olitc,  and  wealden  groups  : 
4th.  The  creta'ceous,  embracing  the  lower  greensand,  gault,  upper  green- 
sand,  chalk  marl,  chalk  without,  and  chalk  with  flints. 

7.  Fourth.     The  tertiary  formations,  which,  being  more  re- 
cent, covered  all  the  preceding  formations ;  they  date  from  a  period 
when  animals  and  plants  belonging  to  all  the  great  classes  existed, 
but  still  anterior  to  the  creation  of  man  : 

The  tertiaries  are  suhdix'ided  into  three  groups  ; 

1st.  The  older  tertiary  or  eocene,  which  embraces  the  London  clay,  bag- 
shot  sand,  and  Paris  Basin. 

2d.  The  middle  tertiary,  or  miocene,  which  embraces  the  Coralline  crag, 
Red  crag,  the  Molasse  of  Switzerland,  &c. 

3d.  The  newer  tertiary,  or  Pliocene,  which  embraces  Norwich  crag,  the 
sub-Apennine  beds,  the  Brown  coal  of  Germany,  &c.,  as  well  as  the  super- 
ficial deposits,  called  Pleistocene,  consisting  of  diluvium  and  alluvium. 

8.  Fifth.     The  modern  formations,  which  are  contemporaneous 
with  the  existence  of  man  on  the  earth,  ;md  are  still  being  formed. 

The  subdivisions  embrace  : 

1st.  Peat-bogs,  formed  by  the  accumulation  of  the  debris  of  certain  plants. 

2d.  Coral  formations,  from  the  multiplication  of  polypa'ria  as  seen  in  the 
coral  islands  of  the  Pacific. 

3d.  Concretionary  formations,  formed  by  calcareous  and  other  matters, 
found  in  solution  in  the  waters  of  certain  springs,  &c. ;  as  travertin,  stala'c- 
tites,  stala'gmites,  &c. 

4th.  Formations  from  transport  or  drift ;  as  fluviatile,  terrestrial,  or  marine 
alluvions,  dunes,  &c. 

5th.  Humus,  or  vegetable  earth,  formed  directly  by  the  disintegration  of 
other  formations,  and  their  mixture  with  the  products  of  decomposition  of 
plants  and  animals,  spread  in  a  layer  of  more  or  less  thickness,  on  almost 
every  point  of  the  surface  of  the  earth. 

9.  All  these  deposits  are  superposed  one  on  the  other,  in  a  con- 
stant order;  and  if  it  were  possible  to  make  a  sufficient  section  in 
a  part  of  the  globe  where  they  all  exist  together,  we  should  find  a 
succession  of  twenty-seven  stories,  or  layers,  distinguishable  by 
their  different  characters.     But  each  of  the  great  deposits  is  divided 
and  subdivided  into  various  layers,  more  or  less  distinct,  composed 
most  frequently  of  arena'ceous  substances,  clay  and  limestone,  of 
different  degrees  of  consistence,  and  in  beds  of  varying  thickness. 
The  assemblage  of  their  alternate  beds  often  forms  successive  layers, 
several  hundred  yards  thick. 

10.  It  is  evident,  that  if  such  sections  existed  in  the  crust  of  the 
earth,  we  could  see  all  the  beds,  and  easily  distinguish  their  rela- 

7.  From  what  period  do  the  tertiary  formations  date  ?     What  are  the 
divisions  of  the  tertiaries  ? 

8.  From  what  period  do  the  modern  formations  date  ?     What  formations 
are  embraced  in  the  divisions  of  the  modern  formations  ?     How  is  humus 
formed  ? 

9.  What  is  the  arrangement  of  the  several  deposits  composing  the  crust 
of  the  earth  ? 

10.  Why  is  it  difficult  to  distinguish  the  relative  ages  of  deposits? 


184  RELATIVE  AGES  OF  DEPOSITS. 

live  ages  by  their  number  in  the  order  of  succession ;  the  deepest 
being  the  most  ancient,  and  that  forming  the  surface  being  the  most 
modern.  It  would  then  be  sufficient,  in  sections  of  different  depths 
which  would  be  found  elsewhere,  to  count  from  above  downwards, 
to  know  always  where  we  were,  and  even  the  variations  that  a 
determinate  bed  might  undergo  in  different  places  would  offer  no 
difficulty  to  observation.  But  such  is  not  the  case  ;  the  numerous 
escarpments  we  meet,  always  present  us  with  but  a  very  small 
portion  of  the  series,  sometimes  in  one  part  of  its  thickness,  and 
sometimes  in  another ;  we  never  see  the  entire  series ;  and  it  is 
only  by  combining  the  observations  made  in  different  places,  that 
we  have  been  able  to  establish  what  we  now  know,  at  the  same 
time  we  discovered  the  particular  circumstances  of  formation  of 
each  deposit. 

In  consequence  of  the  divisions  of  the  whole,  it  is  conceived,  it  might  be- 
come very  difficult  to  distinguish  them,  and  that  in  presence  of  an  escarp- 
ment one  might  frequently  be  unable,  at  first  sight,  to  decide  on  the  point  in 
the  series  to  which  it  ought  to  be  referred.  Indeed,  different  beds  of  the 
same  nature  which  succeed  each  other  in  the  series,  are  often  very  analogous, 
the  limestones  of  one  story  more  or  less  resembling  those  of  another ;  and 
the  same  is  true  of  different  deposits  of  sandstone  and  clay.  It  also  happens 
that  the  same  deposit  varies  at  different  points  :  here  it  is  a  compact,  and 
there,  an  earthy  limestone  ;  in  another  place  the  same  limestone  is  found 
mixed  with  sands,  and,  further  on,  it  is  nearly  pure  sand,  &c.  The  injection 
of  crystalline  matter  adds  to  the  embarrassment,  by  the  modifications  it 
causes  in  the  texture,  and  even  in  the  nature  of  everything  in  its  vicinity. 
It  is  also  conceived,  that  the  fewer  the  beds  superposed  in  the  same  place, 
the  greater  the  difficulties,  and  they  are  at  a  maximum  when  we  meet  an 
isolated  deposit,  without  knowing  on  what  it  rests,  and  not  being  able  to 
perceive  anything  it  covers :  this  occurs  in  a  great  many  countries.  It 
often  happens,  too,  that  one  or  more  beds  are  entirely  wanting  in  one  locali- 
ty, and  then  the  deposits  which  should  naturally  separate  them,  being  im- 
mediately superposed,  exposes  the  observer  to  attribute  to  the  succeeding 
beds  an  age  very  different  from  that  which  really  belongs  to  them. 

1 1 .  To  obviate  this  difficulty,  we  have  observations  on  the  con- 
tinuity of  beds,  some  of  which  we  can  follow  from  points  where 
they  present  certain  characters,  to  others  where  they  offer  different 
characters;  from  points  where  they  are  entirely  isolated,  to  others 
where  we  can  see  on  what  they  rest,  and  what  covers  them,  &c. 

We  have  also  observations  on  stratification  and  inclination  of  different 
beds  towards  one  point  or  the  other,  which  enable  us  to  infer  that  such  a 
species  of  deposit  passes  below  or  above  another,  found  isolated  or  at  a  dis- 
tance. Fragments  and  rolled  flints  may  evidently  indicate  the  priority  of 
deposits  which  contain  them,  to  those  from  which  they  came,  and  thus  fur- 
nish a  good  means  of  distinction,  when  they  are  sufficiently  characterized. 
And  the  nature  of  organic  remains  has  now  become  a  very  decided  aid  in 
distinguishing  different  formations. 

12.  Different  kinds  of  stratification.     There  are  two  kinds  of 

11.  How  are  we  enabled  to  judge  of  the  relative  ages  of  deposits  ? 

12.  How  many  kinds  of  stratification  are  described  ?     What  is  observed 
in  inclined  stratification  ? 


DIFFERENT  KINDS  OF  STRATIFICATION.  185 

stratification  :  one  horizontal  (which  is  the  natural  stratification), 
according  to  which  all  transported  matters  are  deposited  under 
water ;  the  other  more  or  less  inclined,  resulting  from  upheavals 
which  have  taken  place  at  different  epochs.  In  the  latter  we  dis- 
tinguish the  degree  of  inclination,  or  dip,  which  may  be  vertical, 
and  the  point  of  the  horizon  towards  which  the  beds  dip.  The 
last  part  of  the  observation  determines  the  direction  of  the  crests  of 
the  strata,  or,  as  we  say,  the  strike  or  direction  of  the  strata,  which 
is  always  at  right  angles  to  the  dip  or  direction  of  the  inclination, 
and  which  also  indicates  the  direction  of  the  movement  by  which 
the  effect  was  produced.  But  the  first  observation  of  horizontal,  or 
inclined  strata,  is  not  always  sufficient ;  it  is  frequently  necessary 
to  distinguish  the  relative  stratification  of  different  deposits,  which 
is  reduced  to  the  concordance,  or  the  discordance  which  may  exist 
between  them. 

13.  The  dip  of  strata  is  the  point  of  the  compass  towards  which 
they  slope,  while  the  angle  they  form  with  the  plane  of  the  horizon 
is  called  the  angle  of  dip.     The  term  dip  refers  to  the  inclination 
of  a  stratum,  and  the  term  strike  is  used  to  express  its  direction. 
Thus,  strata  may  dip  to  the  north  at  an  angle  of  forty-five  degrees  ; 
in  this  case,  the  strike,  or  line  of  bearing,  must  necessarily  be  east 
and  west,  because  the  strike  is  always  at  right  angles  with  the  dip. 
"  Dip  and  strike  may  be  aptly  illustrated  by  a  row  of  houses  run- 
ning east  and  west,  the  long  ridge  of  the  roof  representing  the 
strike  of  the  stratum  of  slates,  which  dip  on  one  side  to  the  north, 
and  on  the  other  to  the  south."     The  angle  formed  by  the  roof 
with  the  plane  of  the  horizon  would  be  the  angle  of  dip. 

14.  Conformable  stratification.    When  all  the  strata  of  a  forma- 
tion are  parallel  to  each  other,  that  is,  when  there  is  a  concordance 
between  them,  whatever  may  be  their  general  position,  horizontal 
or  inclined,  convex  or  concave,  they  are  said  to  be  conformable 
(Jigs.  293  to  296). 

Fig-.  293.  Fig-.  294.  Fig-.  295.  Fig-.  296. 


Different,  kinds  of  conformable  stratification. 

15.  Unconformable  stratification.  When  the  strata  of  a  forma- 
tion are  not  parallel  to  each  other,  when  there  is  a  discordance 
between  them,  as  where  horizontal  strata  come  in  contact  with 

13.  What  is  meant  by  the  dip  of  strata?     What  is  the  angle  of  dip? 
What  is  meant  by  the  term  strike  ? 

14.  What  is  meant  by  conformable  stratification  ? 

15.  What  is  meant  by  unconformable  stratification  ?     Is  it  always  of  the 
same  character  ? 

16* 


186 


UNCONFORMABLE  STRATIFICATION. 


inclined  beds  (Jig.  297),  or  where  the  relative  inclination  of  beds 
is  different,  as  at  a  and  b  (Jig.  298),  they  are  said  to  be  uncon- 
forrnable.  Where  a  superior  deposit,  whether  stratified  or  not, 
rests  on  a  section  of  the  beds  of  an  inferior  deposit  (Jig.  299),  there 
is  a  peculiar  kind  of  unconformable  stratification,  sometimes  called 
transgressive  stratification.  There  is  another  kind  of  unconform- 
able stratification,  where  the  beds  are  parallel ;  this  occurs  where 
a  horizontal  deposit,  after  having  been  furrowed  in  different  ways 
by  water,  is  again  entirely  covered  by  a  deposit  of  the  same  nature 
which  fills  up  all  the  excavations  (Jig.  300).  In  this  case  the 
strata  are  unconformable  where  they  join  end  to  end  with  beds  on 
the  slope  of  ancient  valleys. 

Fig.  297.  Fig.  298.  • 


Fig.  299. 


b 
Fig.  300. 


Examples  of  unconformable  stratification. 

16.  To  ascertain  the  relations  in  the  stratification  of  two  deposits, 
it  is  necessary  to  pay  great  attention  to  the  particular  structure  of 
the  beds,  which  in  certain  cases  may  lead  us  into  error.  For  ex- 
ample, seeing  that  the  divisions  of  the  bed  «,  (fig.  301),  dip  to- 
wards the  left  of  the  figure,  we  must  not  conclude  that  the  strati- 
fication is  unconformable  with  the  bed  b ;  this  appearance  results 
altogether  from  the  structure  which  the  bed  a  owes  to  its  rapid 
formation  under  particular  circumstances.  (See  page  138.) 
Fig.  301.  Fig.  302. 


Examples  of  doubtful  stratification. 

17.  Schistose  substances  often  present  many  difficulties,  in  this 
respect,  because  their  divisions  run  in  every  direction,  and  some- 
times the  least  apparent  is  the  real  stratification.  For  instance,  we 
might  suppose,  the  deposit  a,  (fig*  302),  rested  conformably  on  the 
deposit  b,  and  that  the  mass  c  is  an  unconformable  stratification,  from 
regarding  the  finest  divisions  of  the  schist  as  indicative  of  the  stra- 

16.  What  is  meant  by  doubtful  stratification? 

17.  What  is  false  stratification? 


FALSE  STRATIFICATION.  187 

tification.  But  we  might  also  consider  the  deposit  a  as  unconform- 
able,  and  the  deposit'  c  as  conformable,  from  regarding  the  parallel 
joints.,  i  to  &,  as  those  of  stratification ;  and  it  is  also  possible  to 
view  both  a  and  c  as  unconformable  relatively  to  6,  by  considering 
the  other  joints  as  those  of  the  strata.  It  may  be  often  difficult  to 
decide  ;  nevertheless,  in  general,  the  schistose  division  is  frequently 
a  structure  which  has  perhaps  a  certain  crystallization  of  mica'- 
ceous  matter ;  and  it  is  this  character,  therefore,  among  others,  that 
we  must  ordinarily  select.  Now,  the  joints  of  dislocation,  for  one 
or  the  other  division  must  have  been  thus  produced,  are  splits 
united  arid  well  marked,  often  a  little  open,  which  are  ordinarily 
prolonged  into  several  consecutive  deposits,  ,/ 
while  the  joints  of  stratification  are  more  un-  jlU 
dulated  and  more  adherent.  The  most  irregu-  /// 
lar  undulations  of  true  strata  are  often  tra- 
versed throughout  by  the  schistose  structure 
(fig.  303),  without  alteration.  This  circum- 
stance evidently  shows  that  this  structure  is 
an  effect  posterior  to  the  contortion  of  beds, 
and  may  be  attributed  to  a  metamorphism 
more  modern  than  their  derangement.  The 
extraordinary  divisions  just  mentioned,  are  Fig.3Q3. 

sometimes  termed  false  stratification. 

18.  Organic  remains,  which  are  very  numerous  in  most  sedi- 
mentary deposits,  also   furnish   a   means   of  recognising   strata. 
There  are  some  which  are  peculiar  to  certain  deposits,  and  are 
not  found  elsewhere,  and  which  are  therefore  distinguished  as 
geo gnostic  horizons.     Thus,  the  Silurian  or  Devonian  formations 
are  clearly  recognised  by  the  presence  of  the  remains  of  a  cer- 
tain family  of  crusta'ceans,  named  trilobites  (fig.  4,  p.  28).     The 
Gry'phca  arcua'ta   (fig.  71,  p.  55),   is  found   in  the  has,  and 
only  in  it :  the  ex'ogy'ra  vir'gula  (fig.  109,  p.  65),  belongs  to 
the  upper  part  of  ,the  jura'ssic  formation  ;  baculites  (fig.  130),  and 
turrili'tes  (fig.  131,  p.  72),  begin  and  end  in  the  creta'ceous  period. 

19.  Although  the  remains  of  mollusks  and  small  animals  are 
found  entire,  and  therefore  easily  recognised,  those  of  large  mam- 
mals, &c.,  often  exist  only  in  fragments ;  and,  without  the  neces- 
sary knowledge,  the  family,  genus,  or  species,  could  not  be  dis- 
covered.    But  those  well  acquainted  with  comparative  anatomy, 
and  the  laws  which  govern  in   the  organization  of  animals,  can 
deduce  the  form,  and  even  the  habits  of  an  animal,  often  from  a 
single  bone. 

"  Every  organized  being  may  be  considered  as  an  entire  and  perfect  sys- 

18.  How  do  organic  remains  assist  us  in  distinguishing  the  relative  age 
of  strata  ? 

19.  How  is  it  that  a  portion  of  the  fossil  remains  of  an  animal  enable  us 
to  recognise  its  class  ? 


188  AN  ANIMAL  MAY  BE  KNOWN  FROM  ONE  OF  ITS  BONES. 

tern,  of  which  all  the  different  parts  mutually  correspond,  and  concur  in  the 
same  definitive  action  by  a  reciprocal  re-action.  No  one  part  can  undergo 
a  change  without  a  corresponding  change  taking  place  in  all  the  others  ;  and, 
consequently,  each  part  taken  separately,  indicates  and  gives  the  key  to  a 
knowledge  of  all  the  rest. 

"  Thus,  if  the  stomach  of  an  animal  is  so  organized  as  only  to  digest  fresh 
animal  food,  its  jaws  must  also  be  so  contrived  as  to  devour  such  prey  ;  its 
claws,  to  seize  and  tear  it ;  its  teeth,  to  cut  and  divide  it ;  the  whole  struc- 
ture of  its  locomotive  organs,  to  pursue  and  obtain  it ;  its  organs  of  sense,  to 
perceive  it  from  afar ;  and  nature  must  have  even  placed  in  its  brain  the 
necessary  instinct  to  enable  it  to  conceal  itself,  and  to  bring  its  victim  within 
its  toils.  Such  will  be  the  general  conditions  of  a  carni'vorous  animal ;  they 
must  inevitably  be  brought  together  in  every  species  intended  to  be  carni'- 
vorous, for  its  race  could  not  subsist  without  them  ;  but  under  these  general 
conditions  there  exist  also  special  ones,  relating  to  the  size,  the  habits,  and 
the  haunts  of  the  prey,  on  which  the  animal  is  to  exist;  and  from  each  one 
of  these  special  conditions  there  result  certain  modifications,  in  detail,  of  the 
form  re-quired  by  the  general  conditions ;  so  that  not  merely  the  class,  but 
the  order,  the  genus,  and  even  the  species,  will  be  found  expressed  by,  and 
deducible  from,  the  structure  of  each  part. 

"  In  order,  for  example,  that  the  jaws  may  be  enabled  to  seize  the  prey, 
there  must  be  a  certain  shaped  prominence  for  its  articulation ;  a  certain 
relation  between  the  position  of  the  resistance  and  that  of  the  power,  with 
respect  to  that  of  the  fulcrum  ;  a  certain  magnitude  of  the  muscle  that  works 
the  jaw,  requiring  corresponding  dimensions  of  the  pit  in  which  that  muscle 
is  received,  and  of  the  convexity  of  the  arch  of  bone  beneath  which  it  passes, 
while  this  arch  must  also  possess  a  certain  amount  of  stiength,  to  enable  it  to 
bear  the  strain  of  another  muscle. 

"That  the  animal  may  be  enabled  to  carry  off  its  prey,  a  certain  degree 
of  strength  is  necessary  in  the  muscles  which  support  the  head  ;  whence 
results  a  peculiar  structure  in  the  vertebrae  to  which  these  muscles  are  at- 
tached, and  in  the  back  of  the  skiill  where  they  are  inserted. 

"  That  the  teeth  may  be  adapted  to  tear  flesh,  they  must  be  sharp ;  and 
they  must  be  more  or  less  so,  exactly  according  as  they  are  likely  to  have 
more  or  less  flesh  to  tear,  while  their  bases  must  be  strong  in  proportion  to 
the  quantity  of  bone,  and  the  magnitude  of  the  bones  they  have  to  break. 
Every  one  of  these  circumstances  will  have  its  effect  on  the  development  of 
all  the  parts  which  assist  in  moving  the  jaw. 

"  That  the  claws  may  be  able  to  seize  the  prey,  there  must  be  a  certain 
amount  of  flexibility  in  the  toes,  and  of  strength  in  the  nails  ;  and  this 
requires  a  peculiar  form  of  the  bones,  and  a  corresponding  distribution  of  the 
muscles  and  tendons  ;  the  fore-arm  must  possess  a  certain  facility  in  turning ; 
whence  also  result  certain  forms  of  the  bones  of  which  it  is  made  up;  and 
these  bones  of  the  fore-arm,  articulating  to  the  humerus,  cannot  undergo 
change  without  corresponding  changes  taking  place  in  this  latter  bone.  The 
bones  of  the  shoulder  also  require  to  have  a  certain  degree  of  strength,  when 
the  anterior  extremities  are  to  be  used  in  seizing  prey  ;  in  this  way  again 
other  special  forms  become  involved.  The  proper  and  free  play  of  all  these 
parts  requires  certain  proportions  in  all  the  muscles  concerned  in  the  mo- 
tions of  the  fore-leg,  and  the  impression  of  the  muscles  so  proportioned  will 
determine  still  more  definitely  the  structure  of  the  bones. 

"  It  is  easy  to  perceive  that  similar  conclusions  might  be  drawn  as  to  the 
structure  of  the  posterior  extremities,  which  contribute  to  the  rapidity  of  the 
general  movement  of  the  body ;  or  of  the  vertebrae,  which  influence  the 
facility  of  those  movements ;  and  also  as  to  the  structure  of  the  bones  of  the 
face,  in  their  relation  to  the  degree  of  development  of  the  external  senses.  In 


RELATIVE  AGES  OF  THE  GLOBE'S  CATASTROPHES.  189 

a  word,  the  structure  of  a  tooth  involves  that  of  the  socket  in  the  shoulder- 
bone,  and  of  the  nails,  just  as — to  use  a  mathematical,  but  very  apt  illustra- 
tion— the  equation  to  a  curve  involves  all  the  properties  of  the  curve ;  and 
as  the  curve  may  be  drawn  when  we  know  the  root  of  the  equation,  so  in 
comparative  anatomy,  by  making  each  property  separately  the  base  of  in- 
vestigations, one  may  deduce  all  the  other  properties.  Thus  the  shoulder 
bone,  the  articulation  of  the  jaw,  the  thigh-bone,  or  any  other  bone,  taken 
separately,  gives  the  structure  of  the  tooth,  or,  conversely,  from  the  tooth, 
a  knowledge  of  these  peculiarities  may  be  derived  ;  so  that,  taking  any  one 
bone,  he  who  is  familiar  with  the  laws  of  the  animal  economy,  may  repro- 
duce the  whole  animal." — Ansted. 
RELATIVE  AGES  OF  THE  PRINCIPAL  CATASTROPHES  OF  THE  GLOBE. 

From  observations,  it  would  seem  that  the  dry  land  must  have  appeared 
in  successive  portions,  to  cause  on  the  surface  all  the  variations  of  nature, 
form,  humidity,  and  dryness,  the  combination  of  which  should  procure  for 
man  all  the  happiness  designed  for  him  by  the  Creator.  The  study  of  the 
successive  appearances  of  land  is  now  one  of  the  most  beautiful  points  of 
view  in  which  geology  can  be  presented ;  we  are  indebted  to  M.  Elie  de 
Beaumont  for  pointing  out  the  course  to  follow,  to  establish  the  chronological 
order  of  the  principal  catastrophes  which  happened  in  Europe,  and  around 
which  all  facts  of  the  same  nature  may  be  grouped. 

As  soon  as  we  perceive  some  part  of  inclined  sedimentary  beds,  we  may 
decide  that  they  have  been  displaced  from  their  ordinary  position  by  up- 
heaval. The  period  of  this  accident  remains  at  first  undetermined  ;  but  if, 
at  the  base  of  more  or  less  elevated  projections  which  these  beds  produce,  we 
find  other  sediments  deposited  in  horizontal  strata, 
resting  against  the  preceding  (Jig.  304),  it  be- 
comes evident  that  the  upheaval  of  the  first  took 
place  after  the  formation  of  the  second,  which  are 
still  found  as  they  were  when  deposited  from  p-  ^Q^ 

water.     We  now  have  a  term  of  comparison,  and, 

if  we  succeed  in  recognising  the  relative  age  of  the  horizontal  deposit,  we 
also  have  an  epoch  of  the  catastrophe,  relatively  determined,  which  pro- 
duced the  uptilting  of  the  other.  These  differences  of  stratification  are 
everywhere  seen  on  the  sides  of  mountains,  and  we  then  see  that  the  several 
sedimentary  deposits,  a,  6,  c,  are  not  all  in  the  same  position.  In  certain 
places  the  stratum  a,  for  example,  is  uptilted,  and  the  stratum  b  is  horizon- 
tal ;  in  another,  a  and  b  are  both  uptilted,  and  c  is  horizontal ;  in  a  third,  a, 
6,  and  c,  are  uptilted  together,  and  another  stratum,  d,  rests  upon  them.  We 
must  infer,  from  these  observations,  that  a  first  upheaval  took  place  after  the 
formation  of  a,  and  before  that  of  b;  a  second  took  place  between  the  strata 
6  and  c,  a  third  between  c  and  d,  &.C.,  and  so  on,  chronologically,  as  far  as 
they  have  been  observed. 

Systems  of  upheaval.  If  the  inclined  position  of  sedimentary  strata  reveals 
to  us  the  existence  of  upheavals,  the  strike  or  direction  of  these  beds,  which 
is  nothing  but  the  line  produced  by  their  swelling  upwards  or  the  crest  or 
ridge  resulting  from  their  rupture,  shows  us  the  course  followed  by  the  phe- 
nomenon. Hence  it  follows  we  may  take  one  fact  for  the  other,  as  the  basis 
of  observation,  and  that  the  different  directions  (strikes)  of  mountain  chains, 
are  also  indications  of  the  different  kinds  of  upheaval.  In  fact,  it  has  been 
long  and  perfectly  established,  on  one  hand,  that  the  inclination  of  strata  is 
intimately  connected  with  the  direction  of  chains,  excepting  the  perturba- 
tions which  result  from  crossings ;  on  the  other  hand,  we  now  know  that 
the  phenomenon  of  uptilting  of  a  determinate  number  of  beds  extends  as  far 
as  the  chain  itself.  It  has  also  been  ascertained,  at  least  for  Europe,  that 
parallel  chains  correspond,  in  general,  in  the  epoch  of  upheaval ;  that  is,  m 


190  SYSTEMS  OF  UPHEAVAL. 

these  chajns,  strata  of  the  same  age  are  found  every  where  uptilted,  and  that 
the  succeeding  ones  are  horizontal.  It  follows  from  this  circumstance  that 
an  upheaval  does  not  take  place  purely  on  a  mathematical  line,  but  on  a 
band  of  formations  more  or  less  wide,  on  which  it  is  manifested  by  several 
parallel  ridges.  The  same  line  does  not  continue  always  from  one  end  to 
the  other,  but  we  find  here  and  there  high  and  low  parts,  and  those  which 
are  concealed  by  subsequent  deposits  ;  therefore,  it  is  the  common  line  of 
all  the  elevated  ridges  which  must  be  taken  for  the  general  direction  or 
strike — (The  word  strike  is  formed  from  the  German  streichen,  to  stretch, 
to  extend). 

20.  The  assemblage  of  directions  on  the  same  line,  and  paral- 
lel directions,  form  what  is  called  a  system  of  upheaval,  which  is 
synonymous  with  the  expressions,  system  of  fractures,  system  of 
uptilted  tfeds,  and  even  system  of  mountains,  although  in  a  more 
restricted  sense  than  in  geography.  To  designate  the  different 
systems,  the  names  of  places  in  which  each  system  is  particularly 
developed  have  been  borrowed  ;  we  say,  system  of  the  Pyrenees, 
system  of  the  Western  Alps,  &c. 

The  great  catastrophes  which  have  successively  opcurred  on  the  surface 
of  the  globe  appear  to  have  always  taken  place  suddenly.  At  greater  or  less 
distances  from  places  where  the  stratification  is  unconformable,  we  often  find 
the  same  deposits  in  conformable  stratification,  and  even  joined  to  each 
other  by  a  gradual  passage ;  hence,  it  follows  that  deposition  has  not  been 
suspended,  but  the  movement  of  the  soil  has  been  local  over  a  more  or  less 
considerable  space  of  the  terrestrial  surface,  and  the  interval  during  which 
it  took  place  must  have  been  extremely  short.  This  is  clearly  seen,  for 
example,  at  the  period  of  the  system  of  the  Rhine,  in  which  the  vosgean 
sandstone  is  found  upheaved,  without  the  bunter  sandstein  having  partici- 
pated in  the  action  ;  and,  nevertheless,  at  a  short  distance  the  two  arena'- 
ccous  deposits,  where  their  stratification  is  conformable,  are  so  joined  to 
each  other,  that  it  cannot  be  determined  where  one  begins  or  the  other  ends. 
The  same  is  the  case  with  the  creta'ceous  formations ;  if  their  different 
deposits  are  dislocated  in  a  certain  direction,  they  are  conformable  for  great 
extents,  and  they  then  pass  from  one  to  the  other  in  such  a  manner  that 
they  were  for  a  long  time  confounded  as  a  single  formation. 

Submerged  and  uncovered  formations. — Sedimentary  beds  found  resting 
horizontally  on  the  sides  of  mountains,  show  that  the  sea  beat  against 
escarpments  by  deposits  upheaved  in  an  anterior  epoch ;  hence  the  expres- 
sion of  the  sea  of  this  or  that  formation,  as  the  creta'ceous  sea,  the  jura'ssic 
sea,  &c.,  which  indicate  the  waters  beneath  which  each  of  these  sedi. 
mentary  deposits  was  formed.  When  a  deposit  is  wanting  in  a  certain 
extent  of  formation,  we  shonld  infer  the  formation  was  then  above  the  sea 
of  the  epoch,  and  formed  there  a  more  or  less  elevated  island  or  continent ; 
thus,  at  the  lime  when  the  Parisian  limestone  was  formed,  a  great  part  of 
France,  and  indeed  of  Europe,  must  have  been  dry,  as  we  scarcely  see 
traces  of  these  deposits  anywhere  except  in  the  neighbourhood  of  Paris  or 
Bordeaux.  But  it  also  happens  that  the  deposits  which  we  must  regard 
as  having  been  dry  at  a  certain  time,  were  afterwards  covered  by  marine 
sediment,  more  modern  than  the  preceding  ;  and  hence  we  must  conclude 
that,  although  uncovered  prior  to  the  anterior  formation,  they  must  have 
afterwards  sunk  to  receive  new  deposits :  such  sinkings  make  certain  catas- 
trophes particularly  remarkable. 

20.  What  is  meant  by  "system  of  upheaval"?  What  is  meant  by  cre- 
ta'ceous sea?  How  are  the  several  systems  of  upheaval  classed  ? 


EPOCHS  OF  EUROPEAN  FORMATIONS.  101 

The  several  systems  of  upheaval  have  been  classed  according  to  their 
direction,  and  the  epochs  in  which  they  occurred.  The  following  table 
exhibits  the  supposed  epochs  of  the  European  upheavals. 

1st,  Lpheaval,  or  system  of  Hnndsruck,  between  the  cambrian  and  silurian  formations. 

2d,        or  system  of  Ballons,  between  the  silurian  and  coal  formations. 

3d,        or  system  of  the  North  of  England,  between  the  coal  and  penine  formations. 

4th,      or  system  of  Hainault,  between  the  penine  and  vosgean  formations. 

5th,      or  system  of  the  Rhine,  between  the  vosgean  and  trias  formations. 

6th,      or  system  of  Thuringerwald,  between  the  trias  and  jnra'ssic  formations. 

7th,      or  system  of  Cote-d'Or,  between  the  jura'ssic  and  greensand  formations. 

8th,      or  system  of  Mont-Viso,  between  the  two  creta'ceous  formations. 

9th,  '  or  system  of  the  Pyrenees,  between  the  upper  chalk  and  Parisian  limestone  " 
10th,  '  or  system  of  Corsica,  between  the  Parisian  limestone  and  molasse  formations, 
llth,  '  or  system  of  the  Western  Alps,  bet.  the  mnlasse  and  siibapennine  formations. 
12th,   '  or  system  of  the  principal  Alps,  bet.  the  subapennine  and  diluvium. 
13lh,  '  or  system  of  Tenare,  between  the  diluvium  and  perhaps  some  modern  alluvions. 

Since  in  Europe  the  different  great  chains  of  the  same  direction,  which 
are  found  on  the  same  line  or  on  parallel  lines,  belong  to  the  same  epoch  of 
upheaval,  there  is  room  to  suppose,  as  nothing  indicates  limits  to  the  phe- 
nomena which  gave  rise  to  them,  that  the  same  effects  were  continued  far 
beyond  the  countries  whose  geological  structure  is  known  ;  hence  it  follows, 
that  wherever  we  find  parallelism  in  the  chains,  we  should  be  led  to  believe 
also  that  the  formations  were  contemporaneous.  It  is  at  least  interesting  to 
examine,  under  this  point  of  view,  the  principal  chains  we  are  acquainted 
with. 

The  direction  of  the  Pyrenees  extends  from  the  Alleghanies,  in  North 
America,  to  the  peninsula  of  India,  through  the  Carpathian  mountains,  a 
part  of  Caucasus,  the  mountains  of  Persia,  from  Erivan  to  the  Persian  Gulf, 
and  through  the  Ghauts,  which  determine  the  position  of  the  coast  of  Mala- 
bar. To  the  south  of  this  line  of  direction  several  parallel  ridges  are  also 
represented  :  those  which  go  from  Cape  Ortegal,  in  Asturias,  to  Cape  Creux, 
in  Catalonia;  the  small  chain  of  Granada,  which  ends  in  Cape  de  Gatte  ; 
the  mountains  which  bound  the  desert  of  Sahara  on  the  north,  cutting  the 
direction  of  Atlas ;  finally,  the  Apennines,  the  Julian  Alps,  the  mountains 
of  Croatia,  of  Romelia,  and  those  of  the  Morea. 

The  system  of  Ballons,  so  near  to  that  of  the  Pyrenees,  appears  to  be 
represented  also  in  the  Alleghanies  :  it  is  to  be  observed  on  the  coast  of 
Brittany,  and  will  no  doubt  be  found  in  several  of  the  groups  just  mentioned, 
when  careful  study  enables  us  to  distinguish  it  from  the  neighbouring 
system. 

The  direction  of  the  Western  Alps  is  remarked  from  the  empire  of  Mo- 
rocco to  Nova  Zembla,  passing  through  the  eastern  coast  of  Spain,  the  south 
of  France,  and  a  great  part  of  the  peninsula  of  Scandinavia.  It  is  recognised 
in  the  Cordillera  of  Brazil,  from  Cape  St.  Roque  to  Montevideo.  Parallel  to 
this  direction  the  same  system  is  seen  in  the  kingdom  of  Tunis,  in  Sicily, 
the  point  of  Italy,  and  in  Asia  Minor.  All  the  shore  of  the  ancient  conti- 
nent, from  North  Cape,  in  Lapland,  to  Cape  Blanco,  in  Africa,  is  parallel  to 
the  direction  of  this  system. 

The  principal  Alps  form  part  of  a  system  of  direction  of  great  extent. 
From  the  chains  of  Spain  and  those  of  Atlas,  in  the  northern  part  of  Africa, 
we  find  parallel  chains  which  extend  to  theChina  sea.  On  this  line  of  direction 
we  find,  starting  from  Sicily  and  Italy,  the  chains  of  Olympus,  in  Greece, 
the  Balkan,  Taurus,  the  central  chain  of  Caucasus,  crowned  by  Elbrouz, 
between  the  Black  and  Caspian  seas,  the  long  series  of  mountains  which 
extend  through  Persia  and  Cabool,  comprehending  Paropamisus,  Hindou- 
koh,  &c. ;  finally,  Himalaya,  the  highest  mountain  in  the  world. 

STATE    OF    EUROPE    AT    DIFFERENT    EPOCHS    OF    FORMATION. 

From  what  has  been  stated,  we  are  led  to  infer  that  the  surface 


192  SILURIAN  AND  DEVONIAN  EPOCHS. 

of  the  globe,  so  often  disturbed,  must  have  presented  great  varia- 
tions in  the  relative  extent  of  land  and  sea,  and  successively  passed 
through  many  different  shapes,  to  reach  its  present  state.  But, 
even  in  Europe,  the  only  part  of  the  world  in  relation  to  which 
positive  information  has  been  obtained,  it  is  very  difficult  to  say 
what  may  have  been  its  condition  in  the  most  ancient  epochs. 
The  reason  of  this  is,  that  having  for  a  long  time  confounded,  under 
the  name  of  transition  formation,  deposits  of  very  different  epochs, 
we  are  not  now  able  to  distinguish,  with  sufficient  clearness 
throughout,  the  limits  of  different  formations  comprised  in-  it.  Nor 
do  wre  know,  and  this  is  a  great  obstacle  to  tracing  the  continents 
of  the  ancient  world,  what  parts  were  successively  sunk  at  each 
catastrophe,  and  the  extent  of  which  we  can  only  know  from  induc- 
tion. It  was  not  until  after  the  appearance  of  the  jura'ssic  forma- 
tion, the  limits  of  which  are  clearly  marked,  that  we  are  able  to 
distinguish,  with  precision,  the  shape  and  extent  of  lands  in  the 
midst  of  seas  in  which  these  deposits  were  formed. 

By  the  term  epoch  of  this  or  that  formation,  we  understand  the 
period  of  time  during  "which  the  formation  was  produced  beneath 
the  sea,  around  the  upheaved  deposits  of  the  preceding  epoch. 
For  example,  the  jura'ssic  epoch  indicates  the  time  during  which 
the  deposits  of  the  Jura  were  formed  in  the  seas  where  the 
upheaved  deposits  of  the  trias  and  all  that  preceded  were  traced. 
The  term,  sea  of  such  an  epoch,  as  jura'ssic  sea,  creta'ceous  sea, 
&c.,  is  often  used  in  the  same  sense. 

Silurian  and  Devonian  epoch.  At  the  time  when  the  Silurian 
and  Devonian  systems  were  formed  in  the  midst  of  seas,  it  is  evi- 
dent there  were  different  portions  of  land  in  Europe  uncovered, 
which  resulted  as  much  from  the  upheaval  of  the  Hundsruck  as 
from  previous  catastrophes :  we  have  seen  those  of  considerable 
extent  which  entirely  escaped  these  deposits,  and  which,  in  conse- 
quence, must  have  been  raised  above  the  waters  in  which  they  were 
formed.  In  France,  there  was  at  least  one  island,  of  the  Cambrian 
formation,  near  the  gulf  of  St.  Malo,  on  a  part  of  Brittany  and  of  Nor- 
mandy; the  great  granitic  plateau,  wrhich  comprises  Limousin,  Au- 
vergne,  &c.,  where  the  upheaval  of  the  Hundsruck  was  manifest  by 
the  direction  of  certain  uptilted  beds  of  gneiss,  and  by  the  anfracluosi- 
ties  in  which  the  coal  formation  was  subsequently  deposited,  must 
have  been,  at  that  time,  above  water,  and,  perhaps  joined,  at  the 
south,  to  the  ancient  group  which  preceded  the  Pyrenees.  The 
mountains  of  Maures  also  existed,  and,  perhaps,  a  part  of  the 
formations  comprised  between  Toulon  and  Inspruck,  in  a  south- 
west and  north-east  direction.  Some  parts  of  the  'centre  of  Vosges, 
and  of  the  Black  Forest,  Eiffel,  the  Hundsruck,  where  the  first 
upheaval  is  clearly  indicated,  and  Ardennes,  were  necessarily 
above  water,  as  well  as  the  county  of  Nassau,  the  Hartz,  all  the 
centre  of  Germany,  including  Saxony,  Bohemia,  and  Moravia. 
The  same  i?  true  of  Scandinavia,  and  a  part  of  the  British  islands. 


COAL  EPOCH.  193 


From  this  moment  lands  were  covered  with  vegetation,  in  arbo- 
rescent ferns,  equisita'cese,  &c.,  sufficiently  abundant  to  form  the 
masses  of  anthracite  found  in  the  Devonian  formation.  The  seas 
were  then  inhabited  by  trilobites,  orthoce'ratites,  orthis,  productus, 
different  kinds  of  terebra'tula  and  several  species  of  polypa'ria, 
of  the  same  genus  as  those  found  in  madreporic  reefs,  which,  as 
well  as  the  tree-ferns,  indicate  a  climate  analogous  to  that  of  the 
present  tropics.  All  these  circumstances  show  that  heat  was  not, 
in  that  epoch,  distributed  over  the  surface  of  the  globe  as  it  now  is. 
Without  doubt,  the  increase  of  temperature,  from  the  surface  to  the 
interior,  was  more  rapid ;  all  springs  were  warm  ;  and,  according 
to  M.  Elie  de  Beaumont,  the  fogs,  which  were  the  result,  hinder- 
ing radiation,  in  the  absence  of  the  sun,  everywhere  tempered  the 
rigour  of  winter,  and  thereby  augmented  the  mean  temperature 
of  the  seasons. 

Coal  epoch.  The  upheaval  of  the  Ballons,  in  bringing  "  to  day" 
the  Silurian  and  Devonian  deposits,  no  doubt,  increased  the  extent 
of  lands,  and  more  or  less  changed  their  configuration.  Vegeta- 
tion must  have  been  prodigiously  developed,  at  that  time,  and  over 
vast  surfaces ;  which  is  proved  by  the  enormous  mass  of  coal 
formed,  and  the  manner  in  which  the  deposits  are  piled  up.  On 
one  hand,  the  carboni'ferous  limestone,  and  the  different  marine 
beds  found  in  the  midst  of  the  sandstone  of  the  coal  formation  itself, 
seem  to  indicate  at  first  a  deep  sea,  and  perhaps  afterwards  an 
immense  maritime  marsh,  which  extended  from  Ardennes  and  the 
Hartz  to  the  ancient  mountains  of  the  British  islands.  On  the 
other  hand,  the  numerous  coal  basins  known  to  exist  in  the  surface 
of  France  and  central  Germany,  clearly  show  there  were  extensive 
lands  on  which  marshes  were  found,  here  and  there,  in  which  were 
formed,  just  as  pcat-bogs  are  in  our  times,  all  the  coal  deposits 
we  have  discovered. 

The  ancient  and  uncovered  formations,  which  constitute  Brittany 
and  the  central  plateau  of  France,  clearly  indicate  high  land,  on 
which  are  found  the  lakes  of  Bayeux,  duimper,  Laval,  and  Vouvant, 
placed  perhaps  in  the  anfractuosities  caused  by  upheaval  of  the 
ballons  ;  then  those  of  Buro-undy,  Limousin,  Auvergne,  Forez,  &c., 
situated  on  a  direction  parallel  to  the  elevation  of  the  Hundsruck. 
This  land,  the  limits  of  which  cannot  be  fixed,  extended  at  least  to 
a  peninsula  towards  Strasburg. 

To  the  east  of  this  land,  and  perhaps  united  to  it,  there  is  another, 
which  was  evidently  uncovered,  because  there  is  nothing  of  the 
penine  formation  deposited  on  it.  The  latter  probably  extended 
over  the  space  no\v  occupied  by  Inspruck,  Milan,  Briancon, 
Genes,  Nice,  Toulon,  and  to  the  island  of  Corsica.  Towards  Toulon 
are  the  marshes  in  which  was  formed  the  coal  now  found  in  that 
part  of  France. 

Lands  also  evidently  existed  over  the  space  occupied  by  Bohe- 

17 


194  COAL  EPOCH. 


mia  and  Saxony,  with  several  coal  lakes  on  their  surface  ;  the  coal 
deposits  of  Moravia  and  Galicia  seem  to  show  their  extension 
towards  those  countries.  There  was  one  island,  at  least,  between 
Cologne  and  Francfort,  presenting  in  its  southern  part  the  great 
coal  basin  of  the  country  of  Treves,  and  uniting,  at  the  north,  with 
the  ancient  formation  of  the  Hartz.  Dry  land  also  existed  in  the 
peninsula  of  Scandinavia,  where  nothing  has  been  deposited  since 
the  Silurian  formations  ;  but  it  seems  to  have  been  sterile,  and 
without  swamps,  for  it  affords  no  trace  of  coal. 

We  are  entirely  ignorant  of  what  existed  where  the  great  cities 
now  stand;  but  the  absence  of  carboniferous  limestone,  out  of  Bel- 
gium and  England,  may  lead  us  to  think  that  a  great  portion  of 
western  Europe  w.as  then  uncovered,  and  perhaps  presented  coal^ 
lakes  which  subsequent  catastrophes  have  sunk  beneath  the  seas. 

A  part  of  the  land  just  mentioned  has  always  remained  unco- 
vered to  the  present  time,  or  has  been  even  upheaved  more  and 
more  by  various  subsequent  catastrophes,  as  Brittany  and  the  cen- 
tral plateau  of  France.  At  certain  points,  in  fact,  coal  deposits 
have  been  pushed  upwards  to  a  great  height,  as  the  plateau  of 
Santa  Fe  de  Bogota,  and  in  the  Cordillera  of  Huarochiri,  where 
some  are  found  from  2700  to  4000  yards  above  the  sea.  In  other 
places,  on  the  contrary,  it  is  evident  the  formations  have  sunk,  to 
be  covered  by  more  modem  deposits,  through  which  the  coal  is 
sought  in  the  depth,  as  at  Anzin,  under  the  chalk,  in  Vosges,  under 
the  red  sandstone,  in  Cevennes,  under  the  jura'ssic  limestone,  &c., 
and,  in  general,  on  the  borders  of  new  formations  exposed  by  sub- 
sequent catastrophes.  Without  doubt,  there  is  some  deeply-buried, 
and  for  ever  lost  to  us,  either  under  different  sediments,  or  under 
water,  as  at  Whitehaven,  in  England,  where  the  mine  extends 
more  than  a  quarter  of  a  league  from  the  shore,  and  a  hundred 
yards  beneath  the  bottom  of  the  sea. 

The  vegetation  of  this  epoch,  favoured,  no  doubt,  by  the  insular 
form  of  the  land,  as  it  now  is  in  all  islands,  consisted  of  lycopodia'- 
ceas,  equisita'cese,  ferns,  &c.,  of  arborescent  species,  the  analogues 
of  which  nre  no  longer  found  except  within  the  tropics,  with  com-, 
fers  resembling  the  araucaria.  The  mass  of  coal  was  formed  of 
their  debris,  with  cellular  cryptoga'mia,  which  then  grew  under 
water,  as  now,  in  peat-marshes,  and  under  a  still  more  favourable 
temperature  for  their  development. 

The  seas  of  this  epoch  had  lost  their  tri'lobites ;  but  contained, 
in  great  abundance,  spi'rifers,  productus,  orthoceras  of  particular 
species,  different  ce'phalopods,  analogous  to  the  nautilus  and  argo- 
naut, and  various  other  shells.  The  encri'nites  were  so  extensively 
multiplied  that  their  debris  constitute,  almost  of  themselves,  certain 
varieties  of  Flemish  and  Belgian  marble.  Sauroid  fishes,  of  great 
size,  and  of  especially  vigorous  organization,  then  existed  ;  and 
the  family  of  sharks,  still  feeble,  presented  cestra'cions  and  hybo- 
dons  (Jigs.  52,  53,  p.  45). 


THE  PENEAN  AND  VOSGEAN  EPOCHS.      195 

The  fresh  waters  which  fed  the  coal  marshes  contained,  as  it 
appears,  few  conchi'ferous  mollusks ;  the  debris,  which  are  rarely 
found,  resemble  anodonta  and  unio'.  Fishes  were  numerous,  in 
some  localities  ;  they  belonged  to  the.  genera  palioni'scus  (fig*  56, 
p.  48),  and  ambly'pterus,  living,  without  doubt,  in  the  rivulets 
which  meandered  at  the  bottom  of  abrupt  fractures  of  the  ancient 
formation. 

Penine  epoch. — The  disturbance  caused  by  the  upheaval  of 
the  north  of  England,  appears  to  have  exerted  more  influence  on 
the  surface,  of  the  then  uncovered  lands,  than  on  their  extent  and 
form.  Only  the  bottom  of  the  sea,  where  the  coal-beds  of  Eng- 
land and  Belgium  were  formed,  was  elevated  in  part  to  escape, 
like  all  France,  to  the  penine  formation.  On  the  other  hand, 
a  small  corner  of  the  south-west  of  Vosges  must  have  sunk 
under  water,  to  receive  the  red  sandstones  which  there  cover 
the  coal  formation.  Further,  in  Mansfield  the  presence  of  the 
penine  formation,  which  is  there  developed  on  a  great  scale  with 
its  shell-limestones,  demonstrate  the  submersion  of  the  country 
beneath  sea-water.  It  was  also  beneath  the  sea,  in  the  county  of 
York,  that  magnesian  limestone  was  deposited,  which  there  repre- 
sents the  whole  formation  of  this  epoch. 

Very  little  is  known  of  the  terrestrial  flora  of  that  time,  for  we 
find  little,  save  the  algae  in  the  bitu'minous  schists  of  Mansfield, 
and  some  sili'cified  trunks  of  co'nifers  in  the  sandstone.  Deposits 
of  coal  suddenly  ceased  to  form,  and  it  seems  from  that  time  there 
were  neither  ponds  nor  rivulets  on  the  lands ;  nevertheless,  there 
were  still  divers  fishes  of  the  genus  palioni'scus,  which  lived  per- 
haps as  well  in  salt  as  in  fresh  water.  The  land  was  for  the  first 
time  inhabited  by  saurian  reptiles  resembling  the  iguana  and  moni- 
tor, the  remains  of  which  are  found  in  the  cuprous  schists.  The 
seas  beneath  which  all  these  deposits  were  formed,  contained  the 
same  genera,  often  the  same  species  of  mollusks  and  radiata  as 
those  in  which  the  carboni'ferous  deposits  were  formed. 

Vosgean  epoch. — The  system  of  Hainault,  in  dislocating  the 
coal  formation  and  ridging  the  surface  of  the  land,  had  little  in- 
fluence on  its  form.  In  the  Vosges  some  of  the  points  where  the 
red  sandstone  was  deposited  were  elevated,  around  Saint-Die, 
Schelestadt,  Montbelliard,  and  escaped  the  succeeding  formations ; 
while  all  the  rest  of  the  chain,  which  had  escaped  the  deposits  of 
the  red  sandstone,  and  consequently  found  elevated  at  this  epoch, 
must  have  been  sunk  now  to  receive  the  vosgean  sandstone :  the 
same  has  taken  place  in  the  Black  Forest. 

Such  was  the  state  of  things  in  this  modification,  that  animals 
could  not  have  lived  on  this  part  of  the  earth,  and  that  plants,  if 
any  then  existed  on  the  surrounding  soil,  could  not  have  been  car- 
ried under  the  waters  except  in  very  small  numbers. 

The  trias  epoch. — After  the  system  of  the  Rhine,  subsequent  to 


196  THE  TRIAS  AND  JURASSIC  EPOCHS. 

which  the  vosgean  sandstone  was  upheaved,  Vpsges  and  the  Black 
Forest  underwent  a  little  change  in  shape  ;  but  other  lands  in 
Europe  have  undergone  scarcely  any  modification.  We  observe 
only  a  secondary  elevation  of  the  central  plateau  of  France  by  the 
porphyroid  granites  of  Lozere,  by  the  hills  which  edge  the  coal 
formation  from  Fins  to  Mauriac.  Subsidences  occurred,  on  the 
other  hand,  in  Bourbonnais  and  Rouergue,  as  well  as  in  lands  be- 
tween Toulon  and  Mice.  Vegetation  then  underwent  great  modifi- 
cations ;  the  ferns  and  equisita'cerc  of  great  height  had  considera- 
bly diminished,  and  coni'fers,  on  the  contrary,  became  more 
numerous  :  plants  analogous  to  za'mia,  and  perhaps  to  cy'cas 
(Jigs.  305,  306),-  then  formed  an  important  part  of  the  flora  of 
Europe,  being  a  prelude  to  the  immense  development  they  took  in 
the  succeeding  epoch. 


Fig.  305. — Za'mia  pungens.  Fig.  30fi. — Cy'cas  revoluta. 

In  this  epoch  new  saurians  appeared,  and  traces  of  birds,  which 
had  not  appeared  in  preceding  epochs,  are  recognised.  It  was  at  this 
period  also  that  those  creatures  existed,  whatever  they  were,  whose 
tracks  are  found  imprinted  on  bunter  sandstein,  freshly  lifted  above 
water.  Mr.  Owen,  who  considers  them  enormous  batrachians, 
supposes  them  to  have  been  of  the  form  represented  (Jig.  307). 

The  jum'ssic  epoch. — At  the  time  of  the  elevation  of  Thurin- 
gerwald  the  tria'ssic  formation,  which  had  just  been  deposited 
beneath  the  sea,  was  upheaved  at  different  points;  some  patches 
of  banter  sandstein  were  added  around  the  central  plateau  of 
France,  between  Moulins  and  La  Chatre,  between  Brives  and 
Tulle,  in  the  environs  of  Rodez,  of  Saint-Affrique  and  of  Lodeve. 


THE  JURA'SSIC  EPOCH.  197 


Fig.  307. — Labyrinthodon  pachygnatus.     (Owen.) 

The  island  of  Var  was  increased  from  these  sandstones  and  con- 
ch ylian  limestone ;  the  Vosges  and  Black  Forest  were  also  con- 
siderably augmented,  the  one  to  the  west,  in  Lorraine,  the  other  to 
the  east,  extending  into  Germany,  and  uniting  various  islands 
which  had  been  separate  till  then.  The  same  was  the  case  with 
different  islets  which  already  marked  the  place  of  the  British 
islands,  and  were  then  united  to  a  continuous  land  by  tria'ssic  depo- 
sits upheaved  between  them,  and  with  them.  But  at  the  same 
time  that  the  new  lands  were  raised  above  water,  there  were  great 
subsidences  in  those  which  previously  existed.  The  land  which 
extended  from  Cherbourg  to  Perpignan,  was  then  divided  towards 
Poictiers,  forming  a  strait,  now  occupied  by  the  jura'ssic  deposits  ; 
it  was  variously  divided  on  its  borders,  and  almost  cut  again  towards 
Rodcz.  That  which  extended  from  Nice  towards  Inspruck  was 
entirely  sunk,  to  receive  the  new  deposit  which  covers  it.  If  per- 
chance there  existed,  at  the  period  of  the  coal,  some  portions  of 
land  where  Paris,  London,  &c.,  now  are,  everything  leads  to  the 
belief  that  they  then  disappeared,  for  the  jura'ssic  formation 
appears  to  be  prolonged  everywhere  beneath  the  soil  which  serves 
them  as  a  base. 

All  the  data  on  the  state  of  western  Europe,  at  the  period  of 
which  we  speak,  are  furnished  by  the  presence  and  disposition  of 
the  jura'ssic  deposits.  Developed  on  a  vast  scale,  and  upheaved 
later  from  the  bosom  of  the  waters,  they  clearly  show  what  was 
then  the  configuration  of  the  lands  around  which  they  were  formed 
under  the  sea. 

The  ocean  of  the  jura'ssic  epoch  also  had  its  peculiar  characters. 
It  was  inhabited  by  saurians,  eminently  swimmers,  the  ich'thyo- 
sau'rus  and  plei'siosau'rus,  whose  paws,  in  form  of  paddles,  remind 
us  of  those  of  the  chelonians  of  the  present  day ;  these  voracious 
animals,  all  aquatic,  took  the  place  of  the  sauroid  fishes  of  the  car- 
boni'ferous  group,  which  had  now  disappeared.  At  the  same 
period  lived  those  flying  saurians,  called  pteroda'ctyls,  which 
peopled  the  air  and  completed  the  series  of  singular  creatures  of  an 
ancient  creation,  now  entirely  annihilated,  the  exterior  forms  of 
which  Dr.  Buckland  has  attempted  to  paint  from  the  skeleton  (fig. 
308). 

These  seas  had  lost  the  productus,  and  spirifers  had  almost  dis- 
17* 


THE  JURA'SSIC  EPOCH. 


Fig.  308. — Restoration  of  the  saurians  of  the  jura'ssic  epoch. 

appeared.  The  numerous  terebra'tulee,  which  lived  in  this  epoch, 
belonged  to  species  entirely  different  from  those  seen  in  the  pre- 
ceding seas  ;  but  there  was  found  a  great  number  of  mollusks  with 
chambered  shells,  in  general  called  ammonites,  the  race  of  which, 
as  yet  little  developed,  had  begun  to  appear  in  the  seas  of  the  trias  ; 
there  existed  bele'mnites,  the  remains  of  which,  until  then  unknown, 
are  numerous  from  the  lias  to  the  chalk  :  and  the  gry'phea  arena' ta 
multiplied  there  for  a  moment,  to  disappear  afterwards,  when  the 
has  was  formed,  and  to  give  place  to  other  species  of  the  same 
genus. 

As  at  present,  coral  reefs  were  formed  in  those  seas,  remains  of 
which  are  found,  showing  a  mean  temperature,  analogous  to  that 
of  our  intertropic  seas. 

On  the  land,  fresh-water  lakes  without  doubt  supported  palu'di- 
na3,  and  fresh-water  streams  carried  helices,  remains  of  which  are 
now  found  in  the  Portland  group. 

There  must  have  existed  also,  on  land,  several  species  of  insects, 
which  served  to  feed  the  pteroda'ctyls,  the  remains  of  which  seem 
to  show  they  were  coleoptera  and  neuroptera,  resembling  the  bu- 
prestes  and  libe'llulse.  Small  marsupial  mammals,  analogous  to 
opossums,  were  met  there,  a  skeleton  of  which  was  found  in  the 
beds  of  Stonesfield.  But  these  creatures  seem  to  have  been  in 
small  numbers,  if  wre  judge  from  the  few  remains  that  have  been 
as  yet  found,  and  no  one  of  the  great  animals  which  characterize 
the  parisian  epoch  has  been  found  with  them. 


CKETA'CEOUS  EPOCH.  HMJ 

The  flora  was  not  the  same  as  that  which  furnished  so  many 
remains  to  the  coal  formation ;  the  lycopodia'ceae,  and  the  gigantic 
ferns  had  disappeared  ;  and  it  seems  that  many  new  species  had 
been  created  after  the  penine  and  tria'ssic  epochs.  Then  the 
cyca'dese  and  co'nifers  considerably  exceeded  all  other  families ; 
and  probably  some  palms  were  already  in  existence,  the  fruits  of 
which  are  found  in  the  lias.  Also  the  carbona'ceous  combustible, 
formed  in  this  epoch,  is  very  different  from  that  of  the  great  coal 
formation.  They  were  at  the  same  time  much  less  abundant, 
which  indicates  a  great  difference  in  the  extent  of  lands. 

Creta'ceous  epoch.  After  the  system  of  upheaval  of  Cote-d'Or, 
which  elevated  a  part  of  the  jura'ssic  deposits  above  the  sea,  the 
form  and  disposition  of  continents  were  considerably  changed. 
The  inferior  limits  of  the  chalk  mark  the  shape  of  lands  which 
then  existed,  and  determine  the  extent  of  the  seas  of  the  epoch. 

The  three  islands  of  the  preceding  epoch  were  now  united,  but 
without  any  change  of  shape.  Brussels,  which  was  inland,  was 
now  found  on  the  coast ;  Arras,  Dunkirk,  Maastricht,  Wesel,  Bres- 
law,  and  Vienna,  were  sunk  under  water.  A  lake  was  formed 
between  Dresden,  Brunna,  and  Prague  ;  a  strait  was  found  in  the 
place  of  Perpignan  and  Carcasonne  ;  and,  what  existed  previously 
to  the  Pyrenees,  was  in  part  submerged. 

By  compensation,  the  Vosges,  washed  by  the  sea  in  preceding 
ages,  was  then  found  in  the  middle  of  the  continent  which  joined 
the  central  island  of  France.  The  space  of  sea  which  separated 
them  was  filled  up.  Langres,  Nevers,  Lyons,  Toulouse,  and  Ox- 
ford, were  on  terra  fir  ma,  and  an  isthmus  was  formed  about  Poic- 
tiers,  to  join  the  great  island  that  existed  to  the  west.  A  shore 
extended  from  the  environs  of  Craco'via,  to  about  Perpignan,  by 
Ratisbonne,  the  position  of  which  was  not  changed,  and  to  Zurich 
and  Lyons.  An  immense  gulf  was  formed  between  Brussels  and 
Oxford,  extending  to  Poictiers. 

Between  Salzbourg  and  Avignon,  a  new  island  was  formed, 
which  marked  the  future  site  of  the  Alps  :  Brian^on,  Turin,  Trente, 
and  Inspruck,  might  have  been  already  placed  there  ;  but  Switzer- 
land was  then  a  channel  which  separated  this  island  from  terra 
firma.  The  island  of  Toulon  was  at  the  time  limited,  and  some 
small  islands  marked  the  environs  of  Marseilles. 

Little  change,  however,  had  taken  place  in  living  creatures.  At 
the  same  time  divers  species  of  ferns  and  cyca'dese  vegetated  on 
the  soil ;  co'nifers,  especially,  became  more  and  more  abundant,  and 
gave  origin  to  masses  of  lignite  found  at  the  base  of  the  chalky 
formations  ;  but  there  were  few  terrestrial  mammals,  for  no  remains 
of  them  are  found  in  the  chalk,  although  they  were  met  with  in 
jura'ssic  deposits.  There  existed,  however,  divers  ceta'cese,  such 
as  lamantins  and  dolphins,  some  of  which  had  already  appeared  in 
the  jura'ssic  seas.  Reptiles  were,  among  the  animals  capable  of 


200  PARISIAN  EPOCH. 


living  on  the  earth,  still  the  most  elevated  creatures  of  the  creation. 
Aquatic  and  terrestrial  species  were  very  numerous ;  among  them 
were  the  iguanodon,  the  megalosau'rus,  and  divers  crocodiles. 
Fluviatile  tortoises,  fishes,  and  mollusks  of  fresh  water,  lived  on  the 
borders  of  lakes,  or  in  their  waters.  The  seas  fed  ba'culites  and 
turriiites,  of  whose  anterior  existence  there  is  no  trace,  and  which, 
towards  the  end  of  the  epoch,  disappeared  at  the  same  time  with 
all  mollusks  having  peculiar  chambered  shells.  Here  and  there 
true  sharks  existed,  and  have  been  continued  to  the  present  time, 
although  their  dimensions  are  considerably  diminished. 

Parisian  epoch.  The  upheaval  of  Mount  Viso,  and  later,  that 
which  gave  birth  to  the  Pyrenees,  to  the  Apennines,  and  all  the 
parallel  chains  we  have  cited,  prodigiously  changed  the  geographi- 
cal constitution  previously  established.  The  last,  especially,  pro- 
duced one  of  the  greatest  convulsions  Europe  has  experienced : 
everything  was  shaken  by  it,  and  the  greatest  part  of  what  was 
then  under  water,  was  elevated  above  it,  to  form  an  immense  con- 
tinent. This  proves  the  little  extension  of  the  parisian  sediments 
then  formed,  and  which  are  found  concentrated,  one  part  in  Bel- 
gium, Artois,  Picardy,  Isle  of  France,  Normandy,  and  the  opposite 
coasts  of  England  ;  and  the  other,  in  the  environs  of  Bordeaux  : 
very  few  traces  are  found  elsewhere.  Hence  it  follows,  that  the 
seas  of  this  formation  did  not  penetrate  far  into  this  continent, 
although  they  covered  the  two  capitals  of  the  world  ;  of  the  vast 
ocean  of  preceding  ages  there  only  remained  a  part  of  the  gulf 
already  limited,  about  Cambridge,  Oxford,  Exeter,  Cherbourg, 
Angers  and  Poictiers,  which  was  then  narrowed  in  many  places, 
and  widened  elsewhere  at  the  expense  of  the  ancient  peninsula  of 
Brussels ;  it  probably  communicated  with  some  remains  of  the 
North  Sea.  In  the  middle  were  two  islands  of  chalk,  the  Wealds, 
of  England,  and  the  country  of  Bray,  in  France.  Another  portion 
of  the  gulf  also  remained  between  Bordeaux  and  Dax. 

The  fauna  of  the  land,  at  the  parisian  epoch,  was  very  different 
from  what  it  had  been  in  preceding  epochs.  The  gigantic  sau- 
rians  had  disappeared,  but  there  remained  great  fresh-water  cro- 
codiles, marine  and  lacu'strine  chelonians,  and  the  earth  was 
inhabited  by  mammals.  The  last  were  then  pach'yderms,  analogous 
to  tapirs,  as  the  anoplothe'rium  and  paleothe'rium,  which  must 
have  been  nearly  of  the  form  represented  (fig.  309) ;  they  lived 
at  the  same  time  with  some  carni'vora  of  the  genus  dog,  &c.  Belem- 
nites,  and  all  similarly  chambered  shells,  had  disappeared  from 
the  seas  ;  the  nautilus  only  remained,  and  it  lived  with  the  cere'- 
thium  giga'nteum  (fig.  148,  p.  80),  and  a  multitude  of  species  of 
rnollusk,  more  or  less  resembling  those  of  existing  seas. 

At  this  age  of  our  planet,  the  flora  of  Europe  was  still  modified ; 
the  cyca'dea?  had  disappeared,  and  the  co'nifers,  presenting  still 
new  species,  to  which  were  joined  the  dicotyledons,  were  found, 


PARISIAN  EPOCH.— MQLA6SE. 


201 


a  b  d 

Fig.  309. — Fauna  of  the  epoch  of  the  parisian  formation. 
ileothe'rinin  ma<rnnm.  c.  Anoplothe'rium  commune. 


a  Paleothe'rium  magnum 
b   Paleothe'rium  minus. 


d  Crocodile. 


with  palms,  to  the  centre  of  Europe.  The  last,  which  are  not  jiow 
found  closer  than  Africa,  at  the  nearest  point,  evidently  indicates  a 
mean  temperature,  higher  than  that  we  now  enjoy,  which  must  have 
been  about  72°,  the  present  mean  temperature  of  lower  Egypt. 
This  circumstance  may  be  attributed  to  the  fact  that  the  increase 
of  internal  heat  was  greater  than  at  present,  and  that  the  fogs,  by 
diminishing  radiation,  rendered  the  winters  less  rigorous. 

Water-courses  necpssarily  must  have  existed  on  the  continent, 
and  may  account  for  deposits  of  lignite,  and  the  remains  of  fresh- 
water mollusks,  being  found  in  place  in  the  midst  of  marine  depo- 
sits. We  are  especially  led  to  suppose  that  one  of  these  water- 
courses, emptying  about  Laon  and  carrying  lacu'strine  deposits 
from  Soissonais,  and  another,  somewhere  between  Exeter  and 
Oxford,  formed  the  deposits  of  the  Isle  of  Wight,  at  the  south- 
west of  the  Wealds.  Around  Paris,  some  parts  of  the  sea  must 
have  been  separated  from  the  rest,  at  a  certain  time,  and 
converted  into  a  fresh-water  lake  in  which  the  gypsum  was 
formed. 

Epoch  of  the  molasse. — It  was  after  the  system  of  Corsica  that 
the  molasse  Avas  formed,  and,  in  such  a  manner,  that  it  is 
generally  deposited  where  the  Parisian  limestone  is  entirely 
wranting.  It  follows  that  lands  which  were  then  elevated  above 
the  waters  must  have  necessarily  sunk,  often  to  great  depths,  to 
receive  this  new  formation,  which  is  sometimes  extremely  thick; 
consequently,  great  modifications  of  the  continent  of  the  preceding 
epoch  again  took  place.  Partial  subsidences  must  have  occurred 


202  •  SUBAPENNINE  EPOCH. 

in  many  parts  of  Touraine,  of  Guienne,  of  Gascony,  Languedoc, 
Provence,  Dauphiny,  and  also  in  all  Switzerland,  &c. ;  lakes 
were  formed,  often  extensive,  sometimes  isolated,  and  sometimes 
communicating  with  the  sea ;  and  it  is  this  which  indicates  the 
contemporaneous  deposits,  some  of  which  are  fluviatile,  and  others 
marine.  In  opposition,  more  or  less  considerable  upheavals  took 
place  at  the  same  time  in  many  parts  of  the  northern  gulf,  in  Bel- 
gium, in  Picardy,  in  the  isle  of  France,  and  all  the  coast  of  Eng- 
land. The  marine  limestone,  laid  bare,  escaped  in  all  this  extent 
the  succeeding  deposits,  and  the  sites  of  London  and  Paris  were 
brought  to  light,  although  surrounded  by  water  in  which  the  mo- 
lasse  was  deposited ;  it  was  the  same  in  the  gulf  of  Bordeaux, 
where  all  the  northern  part  of  the  Parisian  formation  was  up- 
heaved, and  escaped  the  deposit  of  the  molasse,  which  is  found  in 
all  the  rest  of  the  present  basin  which  was  from  that  time  sub- 
merged. 

This  epoch  was  accompanied  by  a  new  change  in  the  creatures 
which  lived  on  the  surface  of  the  soil;  and  from  that  moment, 
besides  some  new  species  of  paleothe'rium,  mastodons,  and  the 
dinotherium  gigdnteum,  appeared  in  Europe  (the  last  nearly  of 
the  form  represented,  Jig.  810),  as  well  as  the  rhinoceros,  hippo- 
po'tamus,  monkeys,  and  many  rodents,  as  castors,  squirrels,  &c. 
The  flora  was  principally  composed  of  coni'fers,  wTith  dicoty'ledons, 
which,  however,  had  not  attained,  in  all  probability,  the  develop- 
ment they  acquired  in  the  succeeding  epoch.  There  still  existed 
palms,  the  remains  of  which  are  found  in  deposits  of  lignite,  and 
particularly  in  those  of  Liblar,  near  Cologne,  as  well  as  in  the 
plaster-works  of  Aix. 


Fig.  310. — Restoration  of  the  Dinothe'rium  giga'ntcum. 

Subapennine  epoch. — The  upheaval  of  the  western  Alps  caused 
a  new  disturbance.  Not  only  the  soil  comprised  between  Con- 
stance and  Marseilles,  rendered  mountainous  by  preceding  events, 
suddenly  assumed  a  considerable  height,  and  a  great  part  of  the 
relief  it  now  presents,  but  still  the  movement  extended  over  all 
Europe.  The  greatest  part  of  the  Anglo-French  gulf  was  filled 
by  an  elevation,  which  brought  « to  day"  all  that  is  referred  to  the 


EPOCH  OF  DILUVIUM.  203 

molasse.  It  was  the  same  in  Guienne,  in  Languedoc,  in  Provence, 
in  Piedmont  and  Switzerland  ;  and  the  form  of  the  seas  was  once 
again  changed.  But,  in  time,  great  Jakes  were  formed  in  the  inte- 
rior of  the  lands  :  one,  from  Dijon  to  near  the  Isere  ;  another,  in  the 
southern  part  of  Alsace  ;  and  a  third,  in  Provence,  from  Sisteron 
to  the  borders  of  the  Durance. 

At  that  time  all  the  carni'vora  appeared  of  the  genera  ursus, 
hyena,  felis,  cams,  $*c.,  which  inhabited  caverns  ;  their  remains 
are  not  found  in  the  Parisian  formation ;  their  species  disappeared, 
not  only  from  the  European  continent,  but  from  the  face  of  the 
globe,  in  the  next  epoch.  There  also  appeared  several  new 
rodents,  horses,  ruminants,  and  probably  the  gigantic  edentate  ani- 
mal, with  slow  and  heavy  gait,  the  megathe'rium  (Jig.  178,  p.  92), 
whose  head  and  whole  aspect  were  similar  to  the  sloths,  although 
its  size  was  that  of  the  largest  rhinoceros,  and  its  body  must  have 
been  covered  by  a  bony  cuirass  like  the  armadillo. 

Epoch  of  diluvium.  At  this  time  Europe  took  its  present  form, 
and  its  relief  was  definitely  fixed.  The  upheaval  of  the  principal 
Alps,  in  forming  all  the  chains  which  extend  to  Austria,  in  elevating 
likewise  some  portions  of  the  western  Alps,  also  raised  up  the  soil 
in  a  great  part  of  Europe,  and  especially  caused  the  division  of  the 
waters  between  the  ocean  and  the  Mediterranean.  The  effects  pro- 
duced show  that  enormous  currents  of  water  were  established  in  all 
directions,  which  furrowed  all  the  deposits  then  uncovered  ;  but  the 
volume  of  waters  furnished  by  lakes,  previously  formed  in  the  interior 
of  lands,  whose  barriers  were  no  doubt  broken  in  the  new  catastrophe 
of  upheaval,  was  in  relation  to  the  vastness  of  the  result  produced  ; 
it  must  have  been  prodigiously  increased  by  some  circumstances, 
attributable,  perhaps,  to  the  sudden  melting  of  the  snows,  and  gla- 
ciers then  accumulated  on  the  western  Alps.  The  currents  which 
were  formed,  in  furrowing  the  surface  of  lands,  carried  their  debris 
in  all  directions ;  hence  the  alluvions  of  the  valley  of  the  Rhone, 
of  Crau,  of  the  plains  of  Lombardy,  those  of  Bavaria,  the  valley 
of  the  Rhine,  &c. ;  hence  the  last  configuration  of  the  valleys,  the 
denudations,  and  the  dislocations,  seen  in  so  many  different  places. 
It  is  from  the  upheaval  of  this  part  of  the  Alps,  that  the  separation 
of  France  and  England  appears  to  date,  as  well  as  that  of  Ireland, 
by  ruptures  effected  between  Brest  and  Cape  Lizard,  between 
Caernarvon  and  Dublin.  It  was  then  that  the  Mediterranean  took 
its  present  limits,  in  consequence  of  the  subsidence  of  formations 
which  extended  to  the  south  of  Marseilles,  at  the  epoch  of  the 
parisian  sea.  The  gulf  of  Bothnia  was  perhaps  produced  in  this 
epoch,  since  the  shell  deposits  found  on  some  points  of  the  coast 
are  all  referred  to  the  sub-Apennine  formations. 

But  change  of  configuration  in  the  soil  was  not  the  only  conse- 
quence of  the  appearance  of  the  principal  Alps  ;  this  catastrophe, 
extending  over  a  great  part  of  the  world,  from  the  height  of  Spain 


204  MODERN  EPOCH. 


to  the  centre  of  Asia,  was  marked  by  the  sudden  cooling  of  Euro- 
pean countries  to  their  present  temperature.  From  that  time 
palms  ceased  to  grow  in  Europe,  and  dicotyle'donous  plants  were 
prodigiously  increased.  The  rhinoceros,  elephants,  and  panthers, 
which  had  just  appeared  in  that  part  of  the  world,  became  entirely 
extinct  there  ;  and,  if  the  cavern  bear  is  represented  in  our  present 
bear,  its  size  is  considerably  diminished.  The  fauna  of  that  part 
of  the  world  was  again  completely  changed,  and  replaced  by  that 
we  now  see.  Besides,  it  was  at  this  moment,  probably,  that  man 
appeared  on  the  earth :  in  fact,  on  one  hand,  there  are  no  human 
remains  in  what  has  been  too  lightly  named  dilu'vium,  for  the 
skeletons  of  Guadaloupe  are  of  the  modern  epoch,  and  cannot  be 
reckoned  ;  and,  on  the  other,  the  animals  which  then  began  are 
precisely  those  with  which  man  has  always  lived,  since  historic 
time. 

Modern  epoch.  From  the  epoch  of  the  principal  Alps,  no  general 
geological  disturbance  has  taken  place  in  Europe ;  and  some  volcanic 
eruptions  and  upheavals,  produced  by  earthquakes,  are  the  only 
effects  that  have  been  manifest.  Such,  also,  appears  to  have  been 
the  action  of  the  13th  upheaval,  which  was  revealed  in  the  Morea, 
in  Naples,  Sicily,  and  in  some  parts  of  Provence,  and  which,  per- 
haps, also  determined  the  eruption  of  the  modern  volcanoes  of 
Auvergne  and  Vivarais,  through  ancient  fissures,  the  beautiful 
preservation  of  which  attests  their  posteriority  to  the  great  denuda- 
tions which  followed  the  event  of  the  principal  Alps. 

But  if  scarcely  anything  occurred  in  Europe  after  this  great 
event,  perhaps  it  was  not  the  same  in  other  parts  of  the  \vorld. 
We  may  suspect  that  a  great  part  of  the  immense  mountain  range 
which  extends  through  America,  and  traverses  Asia  from  Kamt- 
schatka.to  the  Birman  empire,  is  the  result  of  a  more  recent  catas- 
trophe ;  this  direction,  at  least,  offers  the  most  extended,  the  most 
decided,  and,  so  to  speak,  the  least  effaced  feature  of  the  exterior 
configuration  of  the  earth.  It  is  there  we  see  the  greatest  number 
of  active  volcanoes,  and  consequently  the  most  extensive  and  best 
preserved  communication  between  the  interior  and  exterior  of  the 
globe,  and  perhaps,  also,  the  greatest  mass  of  volcanic  products 
known. 

Deluge.  The  successive  appearance  of  great  mountain  chains 
has  produced  great  disturbances  in  different  parts  of  the  globe. 
But  it  is  evident  that  these  catastrophes,  at  least  those  of  great 
energy,  and  those  which  extended  over  large  spaces,  as  the  up- 
heavals of  the  Alps,  Pyrenees,  &c.,  must  have  manifested  their 
action  over  all  the  rest  of  the  earth  in  secondary  phenomena 
of  more  or  less  importance.  If  a  simple  earthquake  is  enough  to 
produce  a  violent  agitation  of  the  sea,  a  sudden  irruption  of  waters 
on  continents,  these  terrible  revolutions  could  not  have  failed  to 
cause  more  or  less  impetuous  movements  in  the  ocean,  and  tern- 


DELUGE.  205 


porary  derangement  of  level  of  more  or  less  extent.  Hence,  without 
doubt,  the  extraordinary  inundations,  which,  at  each  catastrophe, 
have  ravaged  the  surface  of  existing  lands,  and  produced,  as  in  our 
day,  various  denudations,  or  superficial  alluvions,  of  more  or  less 
extent. 

Now,  since,  without  counting  all  that  escaped  the  investigations 
of  science,  we  clearly  see,  in  Europe,  a  series  of  successive  move- 
ments of  the  soil,  which  have  modified  the  whole  continent,  and 
many  even  a  whole  hemisphere,  there  is  nothing  absurd  in  admit- 
ting that  what  took  place  at  so  many  different  times,  from  the  most 
ancient  to  the  most  modern  epochs  of  formation,  may  have  happened 
once,  somewhere  after  the  appearance  of  man  on  the  earth.  Con- 
sequently there  is  nothing  contrary  to  reason  in  the  belief  of  a 
great  irruption  of  water  over  the  lands,  a  general  inundation,  a 
deluge,  in  fact,  which  we  find  described  not  only  in  the  Bible,  but 
deeply  impressed  in  the  traditions  of  all  people,  and  at  an  almost 
uniform  date.  Thus,  in  recognising  in  the  recital  of  Moses,  the 
extraordinary  circumstances  which  bear  witness  to  the  supernatural 
intervention  of  the  divine  will,  we  see,  on  one  hand,  the  material 
possibility  of  the  fact  transmitted  to  us,  and,  on  the  other,  we  find 
even  the  secret  of  the  means  brought  into  play ;  that  is,  the  up- 
heavals, the  subsidences,  the  consequent  oscillations  of  the  water, 
which  from  that  time  became  efficient  causes  of  the  great  chastise- 
ment then  inflicted  on  the  human  race.  If,  because  the  known 
results  it  has  produced  are  feeble,  we  cannot  too  carefully  seek  the 
cause  of  this  great  phenomenon,  in  the  last  of  the  upheavals  to  this 
time  classed,  which  dislocated  the  deposits  in  which  traces  of  human 
industry  have  already  been  found  :  perhaps  it  maybe  discovered  in 
that  which  caused  the  rise  of  the  Andes  in  America,  and  the  volcanic 
chain  of  central  Asia,  which,  with  a  colossal  development,  also 
present  striking  characters  of  relative  novelty. 

As  to  the  future  of  our  planet,  everything  leads  to  a  belief  that 
the  state  of  tranquillity  we  now  enjoy  is  but  temporary,  like  all  the 
intervals  of  crises  during  which  the  different  sedimentary  deposits 
were  formed.  In  fact,  in  the  series  of  perturbations  which,  through 
all  time,  have  formed  part  of  the  mechanism  of  nature,  we  perceive 
no  law  authorising  us  to  conceive  a  termination  to  the  succes- 
sion of  these  phenomena  :  to  accidents  of  little  importance  succeed, 
indistinctly,  either  crises  of  the  same  order,  or  frightfu  1  catastrophes  ; 
long  periods  of  tranquillity  suddenly  succeed  terrible  convulsions. 
To  the  small  upheaval  of  mount  Viso,  for  example,  succeeded  the 
great  catastrophe  of  the  Pyrenees  ;  to  this  the  small  accidents  of  the 
system  of  Corsica,  which  were  followed  by  the  great  event  of  the 
Alps.  The  long  period  of  the  jura'ssic  formation  was  disturbed 
by  the  upheaval  of  Cote-d'Or,  as  the  deposit  of  the  vosgean  sand- 
stone was  almost  immediately  arrested  by  the  system  of  the  Rhine. 
18 


206  GEOGENY. 


AH  was  irregular  in  those  revolutions  of  which  we  have  acquired 
a  knowledge ;  no  fact  presents  itself  suggesting  the  idea  of  a 
gradual  diminution  in  the  intensity  of  subterranean  actions,  and 
leading  us  to  think  the  earth  has  lost  the  property  of  being  suc- 
cessively broken  and  ridged  in  all  directions.  Nothing,  therefore, 
can  assure  us  that  the  period  of  calm  in  which  we  have  lived  for 
upwards  of  5000  years  (the  period  of  the  deluge),  will  not  be  dis- 
turbed, in  its  turn,  unexpectedly,  by  the  appearance  of  some  new 
system  of  mountains  ;  the  effect  of  a  new  dislocation  of  the  soil,  the 
foundations  of  which  earthquakes  show  not  to  be  unshakable. 
Hence  it  follows  that  the  idea  of  an  end,  or  a  renewal  of  things 
here  below,  as  widely  spread  as  the  great  inundation  which  has 
passed,  is  also  in  the  order  of  the  laws  which  govern  the  universe. 

Geogeny.  The  history  of  the  various  systems  which  have  been 
imagined  to  explain  the  origin  of  the  universe,  and  of  the  earth  in 
particular,  might  perhaps  afford  some  attraction  to  the  curious  ;  but, 
besides  occupying  a  great  deal  of  time  in  pure  romance,  it  is,  per- 
haps, better  to  forget  the  many  mental  vagaries  we  should  be 
forced  to  expose.  A  single  geogenv  is  worthy  of  our  attention  ; 
it  is  that  which  is  related  in  the  Book  of  Moses,  and  which, 
after  a  lapse  of  more  than  3000  years,  still  presents,  on  one 
hand,  the  clearest  application  to  the  best  established  theories, 
and,  on  the  other,  the  most  succinct  account  of  great  geological 
facts. 

What  is  more  rational,  in  fact,  and  more  in  conformity  with 
even  our  most  precise  knowledge,  when  we  think  of  bringing  order 
into  the  general  confusion  of  things,  than  to  create  the  vehicle  by 
means  of  which  the  phenomena  of  light,  of  heat,  &c.,  may  be 
manifest,  and  infuse  life  everywhere, — than  to  collect  the  scattered 
elements  into  groups  separate  from  each  other, — than  to  establish 
here  and  there  centres  of  attraction  around  which  all  may  gravitate 
according  to  an  immutable  law  ?  Nevertheless,  this  is  what  we 
find,  with  fewer  details,  no  doubt,  than  we  could  give  by  means  of 
our  acquired  knowledge,  in  brief  and  common  language  intelligible 
to  all,  in  the  first  verses  of  Genesis,  which  thus  state  three  succes- 
sive and  distinct  facts.  We  there  find,  indeed,  in  outline :  Dens 
fecit  LUCEM  (the  fluid  of  light,  of  heat,  &c.),  FIRMAMENTUM  (space, 
and  all  the  masses  scattered  through  it),  SOLEM  ET  STELLAS  (the 
centres  of  attraction),  &c. 

As  to  the  organic  creation,  it  is  divided  into  four  successive,  and 
also  rational  epochs.  The  first  established  vegetative  fife,  or  life 
of  nutrition,  which  is  manifested  not  only  in  plants,  but  also  in  the 
inferior  animals,  in  which  we  find  scarcely  any  other  phenomena 
than  those  of  nutrition,  growth,  &c.  Afterwards  came  the  life  of 
relation  or  sensibility,  instinct,  intelligence,  and  will,  successively 
added,  in  different  proportions,  to  the  phenomena  of  simple  existence. 


GEOGENY.  207 


This  new  life  first  takes  a  certain  development  in  fishes  (including 
reptiles,  no  doubt),  then  birds,  which,  together,  constitute  the  second 
epoch  of  creation.  It  acquired  a  new  extension  in  mammals,  which 
appeared  at  a  third  epoch  ;  and  finally  reached  its  highest  degree 
in  man,  with  whom  terminated  the  work  of  the  OMNIPOTENT, 
receiving  a  soul  in  the  image  of  God,  to  distinguish  him  from  all 
other  creatures. 

This  is  without  doubt  a  wonderful  example  of  successive  organic 
combinations ;  but  it  is  also  precisely  the  order  in  which  all  the 
remains  buried  in  different  ages  successively  present  themselves. 
Those  we  meet  in  deposits  we  regard  as  the  most  ancient,  are  the 
calcareous  remains  of  certain  polypa'ria,  mussels,  sometimes  even 
the  shell  of  some  acephalous  mollusks,  the  trilobite  crusta'ceans, 
and  the  remains  of  plants,  the  accumulation  of  which  formed  the 
anthracite  of  the  devonian  formations.  The  abundance,  the  extent, 
the  thickness  of  these  combustible  beds  announce  the  great  luxu- 
riance of  vegetation,  which  leads  us  to  believe  that  plants  existed 
for  a  long  time,  and  that  perhaps  their  first  debris  have  disappeared 
in  the  profound  metamorphisms  which  modified  the  deposits  in 
which  they  might  have  been. 

Fishes  are  not  met  with  prior  to  the  devonian  formations,  and  it 
is  only  in  the  coal  deposits  they  present  a  strength  of  organization, 
which  is  lost  in  the  succeeding  deposits,  and  which  is  not  known 
even  now  on  the  globe.  Reptiles  have  left  their  remains  in  the 
new  red  sandstone,  or  penine  formations  which  followed  ;  and  the 
birds,  the  creation  of  which  Genesis  also  places  in  the  same  epoch, 
have  left  the  imprints  of  their  feet  on  the  sandstones. 

Mammals  did  not  appear  until  long  afterwards  ;  the  traces  of 
those  found  in  the  great  o'olite  belonged  to  the  least  perfect  orders: 
it  is  only  in  the  tertiary  strata  that  their  debris  of  every  species  are 
found  in  abundance. 

Human  remains  are  not  found  in  any  of  the  beds  which  have 
been  upheaved  from  the  bosorn  of  the  waters,  and  now  forming 
parts  of  our  continents;  it  therefore  follows  that  this  privileged 
being  of  the  general  creation  did  not  appear  on  the  globe  until  after 
the  animals  whose  fossil  debris  have  been  found ;  he  dates  from 
an  epoch  comparatively  very  recent,  which  is  placed  after  the  up- 
heaval of  the  principal  Alps ;  his  formation  would  consequently 
go  back  about  6800  years,  according  to  admitted  chronology. 
It  is  in  deposits  formed  under  the  waters  since  this  catastrophe 
that  the  bones  of  man  should  be  found,  and  they  will  not  appear 
from  that  time  in  the  series  of  geological  beds  until  new  revolu- 
tions shall  have  transformed  the  sediments  still  found  under  water 
into  dry  land. 

It  is  clear  from  this  outline  that  the  brief  statement  of  sacred 
history  is  entirely  in  conformity  with  geological  generalities.  Ob- 


208  GEOGENY. 


scrvation  alone  enables  us  to  add  a  great  number  of  details, 
useless  no  doubt  to  most  men,  but  interesting  at  least  to  the  small 
number  of  those  who  dedicate  themselves  to  study,  if  indeed 
they  are  not  destined  perhaps  to  enlighten  their  belief. 

The  assemblage  of  data  we  now  possess  leads  us  to  perceive 
that  each  of  the  particular  creations  briefly  indicated  in  Genesis, 
with  the  exception  of  that  of  man,  did  not  take  place  in  a  single 
moment ;  that,  on  the  contrary,  it  was  successively,  in  a  considera- 
ble space  of  time,  and  in  proportion  as  the  terrestrial  globe  itself 
was  fashioned.  Indeed,  if  the  vascular  cryptoga'mia  appeared 
nearly  from  the  commencement  of  things,  the  gy'mnospe'rmous 
phaneroga'mia  did  not  appear  until  about  the  epoch  of  the  coal 
formation,  and  did  not  exist  in  abundance  until  long  afterwards  ; 
it  is  the  same  with  the  monocotyledons,  the  remains  of  which  are 
at  first  few  and  indistinct,  and  not  clearly  seen  until  after  the  chalk ; 
the  dicotyledons  did  not  appear  until  still  later,  in  the  midst  of  the 
tertiary  formations.  In  all  this  interval  of  time,  the  species  suc- 
cessively changed,  and  those  which  were  created,  have  in  turn  also 
entirely  disappeared,  one  after  the  other,  to  give  place  to  the 
new. 

Fishes,  reptiles  and  mollusks,  respectively  present  us  with  the 
same  phenomena,  and  still  more  clearly  show  the  successive  ex- 
tinctions of  different  races,  and  the  appearance  of  many  others. 
The  sauroid  fishes,  which  lived  at  the  time  that  coal  was  formed  in 
Belgium  and  England,  disappeared  for  ever  in  the  new  order  of 
things,  established  in  the  penine  formation.  True  sharks  did  not 
exist  then,  but  appeared  long  after  in  the  creta'ceous  sea.  Gigan- 
tic saurians,  with  paws  in  form  of  paddles,  and  flying  saurians, 
existed  in  abundance  in  the  jura'ssic  epoch,  but  disappeared  in 
the  following  period,  and  were  replaced  in  it  by  enormous  ter- 
restrial saurians,  of  which  there  are  no  previous  traces,  and,  after 
long  having  inhabited  the  earth  by  themselves,  the  latter  were 
also  successively  lost,  leaving  only  crocodiles  after  them,  still  very 
different  from  those  of  the  present  day.  The  same  is  true  of  the 
tri'lobites,  productus,  and  spi'rifers,  which,  after  having  multiplied 
for  some  time,  disappeared  one  after  the  other.  The  ammonites  and 
belemnites  succeeded  them,  and  are  found  in  abundance  in  the 
jura'ssic  sea ;  then  they  became  completely  extinct,  after  having 
successively  changed  species,  at  the  moment  in  which  the  chalk 
formation  ceased  to  take  place.  All  the  mollusks  that  followed 
after,  more  and  more  resemble  those  now  existing,  of  which  there 
was  then  no  trace. 

Mammals  present  themselves  under  similar  circumstances  ;  the 
different  orders  and  different  species  appeared  only  in  succession. 
The  first  were  only  the  feeble  marsupials.  Long  afterwards  came 
the  pachyderms,  analogous  to  the  tapir,  the  first  species  of  which 


GEOGENY.  209 


were  soon  annihilated.  Other  species  of  the  same  genus  suc- 
ceeded them,  and  these  were  found  associated  with  new  animals, 
the  ma'stodon  and  dinothe'rium,  but  they  soon  afterwards  became 
extinct  for  ever.  Still  later  came  the  elephants ;  they  only  appeared 
with  the  carni'vora,  the  rode'ntia,  &c.,  the  species  of  which  were 
still  only  the  prelude  to  those  which  appeared  at  the  same  time 
with  man. 

All  these  successive  changes  in  the  series  of  creatures  coincide 
with  the  great  disturbances  of  the  surface  of  the  globe.  It  was  at 
the  instant  of  the  catastrophes,  produced  by  movements  of  the  soil, 
that  families,  genera,  species  of  organic  bodies  which  had  until 
then  existed,  disappeared.  In  times  of  the  succeeding  calm,  on 
the  contrary,  .the  new  organization  was  developed  in  harmony 
with  the  new  atmospheric  circumstances,  and  new  dispositions 
of  the  isothermal  lines,  &c. 

These  details,  which  observation  enables  us  to  add  to  the 
recital  of  Genesis,  are  in  general  harmony  with  the  facts,  there 
found  briefly  enunciated,  and  of  which  they  are  but  the  develop- 
ment ;  the  only  difficulty  presenting  itself  is  that  of  the  appli- 
cation of  the  word  day,  which,  happily,  even  in  the  eyes  of 
legitimate  judges,  from  Saint  Augustine  down,  does  not  seem  to 
possess  the  value  which  people  have  naturally  attributed  to  it. 
This  expression  seems  in  fact  to  have  been  adopted,  only  as  an  in- 
dication of  relative  epochs,  as  the  means  of  making  understood 
and  retaining  the  order  and  succession  of  things  which  were  at 
once  revealed.  It  is  clear,  indeed,  that  minute  details  categorically 
established  by  figures,  which  would  satisfy  the  curiosity  of  a  small 
number  of  men,  would  not  be  either  received  or  comprehended 
by  the  vulgar,  who,  nevertheless,  are  entitled  to  this  important 
instruction.  We  ourselves  often  resort  to  ways  still  more  crooked 
to  make  ourselves  better  understood  by  all :  it  is  in  this  way,  for 
example,  we  speak  of  the  rising  and  setting  of  tfye  sun,  to  describe 
the  arrival  of  this  luminary  to  the  meridian,  to  the  solstice,  &c., 
although  we  know  very  well  that  we  must  attribute  these  pheno- 
mena to  the  inverse  movements  of  the  earth. 

According  to  geological  observations,  this  common  expression, 
days,  ought  to  signify  epochs,  which  embrace  long  periods  of 
time,  each  being  relative  to  a  certain  system  of  creation  in  which 
there  were  different  formations  of  creatures,  as  well  as  success- 
ive extinctions  of  those  previously  existing.  Each  period  be- 
gan at  a  particular  date,  clearly  determined,  and  marked  by  a 
catastrophe  which  overturned  the  order  of  things  anteriorly  esta- 
blished on  the  earth ;  it  was  extended,  for  a  longer  or  shorter  time, 
sometimes  through  succeeding  epochs,  and  often  up  to  the  appear- 
ance of  man  himself.  According  to  the  conjectures  of  the  scien- 
tific, an  immense  time  elapsed  between  the  formation  of  the  first 
18* 


210  GEOGENY. 


sediment  and  the  last,  without  counting  the  period  required 
for  the  consolidation  and  first  cooling  of  masses  of  planetary  mat- 
ter. It  was  in  long  series  of  ages,  which  are  but  as  instants  in 
eternity,  that  the  earth  was  fashioned,  as  we  now  behold  it,  by 
every  kind  of  movement  in  the  soil,  by  sedimentary  deposits  of 
different  kinds,  and  finally  prepared  as  the  sojourning  place  of 
man,  for  whom  God  has  disposed  everything. 


GEOLOGY. 


GLOSSARY. 


The  following  abbreviations  are  used  : 


Pr.  French 

fr.  fr.  from  the  French 

Ger.  German 

fr.  ger.  from  the  German 

Gr.  Greek 

fr.  gr.  from  the  Greek 

It.  Italian 


ABXO'HMAL —  fr.  lat.  ab, .from,  nor- 
ma,  rule,  Not  conformable  to 
rule. 

ABXO'HMOUS — Out  of  rule;  missha- 
pen. 

ACEPH'ALOUS —  (a-kef'al-us.)  fr.  gr. 
a,  without,  kephqle,  head.  Without 
a  head  ;  headless. 

ACTIN'OLITE  and  ACTY'XOLITE — fr. 
gr.  aktin,  a  ray ;  lithos,  a  stone. 
A  variety  of  hornblende  which 
usually  occurs  in  fascicular  crystals. 
There  are  three  varieties  of  this 
mineral ;  crystallized,  asbestous, 
and  glassy. 

ACULEA'TUS — Lat.  Aculeate  ;  having 
a  sharp  point,  (p.  49.) 

ACUMIX  A'TA  —  Lat.  Acuminate ; 
pointed  ;  peaked,  (p.  59.) 

ACU'TA — Lat.  Acute  ;  sharp  pointed. 

ACUTICO'STA — Lat.  (acutus,  pointed, 
and  costa,  rib.)  Having  pointed 
ribs  or  sides. 

A'CUTTLO'BA — Lat.  (acutus,  pointed  ; 
loba,  a  lobe.)  Having  sharp  or 
pointed  lobes.  (Fig.  169,  p.  88.) 

ADU'LT — Fr.  Lat.  adolesco,  I  grow. 
Full  grown. 

A'GATE  —  fr.  gr.  agathos,  good,  pre- 
cious. An  aggregate  of  certain 
siliceous  minerals,  chiefly  chalce- 
dony, variously  coloured.  Moss 


fr.  it.  from  the  Italian 

Lat.  Latin 

fr.  lat.  from  the  Latin 

Sp.  Spanish 

fr.  sp.  from  the  Spanish 

Plur.  Plural. 


agate  or  Mocha  stone  is  a  chalce- 
dony containing  within,  moss-like 
delineations  of  a  yellowish-brown 
or  green  colour. 

AGGLO'MERATE —  fr.  lat.  agglomero, 
I  wind  up.  To  gather  together. 

AGGLOMEHA'TIOX — A  mass  made  up 
of  parts  gathered  together. 

AGGLUTINATED  —  fr.  lat.  ad  to,  glu- 
ten, glue.  United  together  5  ad- 
hering. 

ALJEFO'RMIS — Lat.  (a/a,  \ving,forma, 
shape).  Wing-shaped.  (.Fig.  119.) 

ALBITE  —  fr.  lat.  albus,  white.  A 
mineral.  See  p.  120. 

ALBITIC — Of  the  nature  of  albite. 

AL'GJE — Lat.  plur.  of  alga.  Seaweed. 
Systematic  name  of  a  family  of 
plants. 

ALLU'VIAL — Of  the  nature  of  allu- 
vium. 

AT.LU'VIOX,  }  fr.  lat.  alluo,    I  wash 

ALLU'VIUM,  5  upon.  Gravel,  sand, 
mud,  and  other  transported  matter 
washed  down  by  rivers  and  floods 
upon  land  not  permanently  sub- 
merged beneath  water.  A  deposit 
formed  from  transported  matter, 
(p.  94.) 

ALPINE — Belonging  or  relating  to  the 
Alps. 

ALU'MISTA  —  fr.  lat.  alurnen,  alunii 
(211) 


212 


GLOSSARY.  — GEOLOGY. 


Pure  argil ;  the  basis  of  alum  ;  one 
of  the  earths. 

ALU'MINOUS — Of  the  nature  of  alu'- 
mina. 

ALVEOLA'TUS — Lat.  Alve'olate.  Hav- 
ing the  surface  covered  with  nu- 
merous depressions,  comparable  to 
the  alve'oli  or  sockets  of  the  teeth. 

AMBLY'PTKRUS —  fr.  gr.  amblus,  ob- 
tuse, pteron,  wing.  A  fossil  fish. 

AMBULA'CRA — Lat.  plur.  of  ambula- 
crum. The  narrow  longitudinal 
portions  of  the  sea-urchin  (Echi- 
nus), which  are  perforated  with  a 
number  of  small  orifices,  giving 
passage  to  tentacular  suckers,  and 
alternate  with  the  broad  tuberculate 
spine-bearing  portions,  (p.  54.) 

AMBTJLA'CRUM — Lat.     An  alley. 

AMMO'NIA — Lat.  Relating  to  Am- 
mon,  a  name  of  Jupiter.  Specific 
name  of  a  fossil  shell,  (p.  67.) 

AMMO'NIS — Lat.  Genitive  case  of 
Ammon,  a  name  of  Jupiter. 

AM'MOXITE —  fr.  lat.  Amman,  (p. 
51.) 

AMO'RPHOUS  —  fr.  gr.  a,  without, 
ntorphe,  form.  Shapeless. 

AM'PHIBOLE  —  fr.  gr.  amphibolos, 
equivocal,  (p.  121.) 

AMPIE'XUS  —  fr.  lat.  ampledo,  I  em- 
brace. Generic  name  of  a  fossil. 

AMPULLA'RTA —  fr.  lat.  ampulla,  a 
round,  swelled  out  bottle.  Name 
of  a  genus  of  snails. 

AMY'GHALOID —  fr.  gr.  amugdalon, 
an  almond,  eidos,  form.  Almond- 
shaped.  Applied  to  certain  rocks 
in  which  other  minerals  are  oc- 
casionally imbedded  like  almonds 
in  a  cake.  A  particular  form  of 
volcanic  rock. 

ANA'LOGY —  fr.  gr.  ana,  between; 
logos,  reason.  Resemblance  or  re- 
lation things  bear  to  each  other, 
although  not  exactly  alike  in  all 
respects. 

ANA'LOGOUS — Having  analogy,  or  re- 
sembling. 

AN'ALOGUE — A  substance  or  article 
having  ana'logy  to  others  may  be 

.    called  the  an'alogue  of  those  things 


with  which  its  properties  or  points 
of  resemblance  are  comparable. 

ANAN'CHYTES — A  genus  of  fossil  sea- 
urchins,  p.  62. 

ANDALU'SITE — A  mineral  first  ob- 
served in  Andalusia  in  Spain.  It 
is  very  hard  and  infusible,  and 
consists  chiefly  of  alu'mina  and 
si'lica. 

AXFRACTUO'SITY — Fr.  Lat.  anfrac- 
tus,  the  bending  or  winding  of  a 
way.  An  irregular  hollow  or 
groove. 

ANGLE  OF  DIP.     See  p.  185. 

AN'HYDROUS  —  fr.  gr.  a,  without, 
udor,  water.  Without  water.  Ap- 
plied to  salts  and  certain  acids 
when  deprived  of  water. 

AN'NULAR  —  fr.  lat.  annulus,  ring. 
Shaped  like  a  ring. 

ANNULA'R*A  —  fr.  lat.  annulus,  ring. 
Generic  name  of  a  fossil  plant, 
(p.  41.) 

ANOIIO'NTA  —  fr.  gr.  a,  without; 
odous  (genitive,  odoutos),  tooth. 
Systematic  name  of  a  kind  of  mus- 
sel, p.  149.  * 

ANODO'KTJE — Plur.  of  Anodonta. 

ANOPLOTHE'IUUM  —  fr.  gr.  a,  with 
out,  oplon,  arm,  or  anoplos,  un- 
armed ;  and  therion,  beast.  P.  82, 
fig.  156. 

AIVTICLI'NAL  AXIS,  ^  fr.     gr.    anti, 

AjrriCLi'uAL  LINE,  5  against ;  kli- 
nein,  to  incline.  An  imaginary 
line  towards  which  strata,  dipping 
in  opposite  directions,  rise.  p.  160. 

AxTiauA'Tus — Lat.  Antiquated,  out 
of  date,  abolished. 

ANTHRACITE — fr.  gr.  anthrax,  char- 
coal. Mineral  charcoal.  A  kind 
of  stone-coal  difficult  to  inflame. 

A'NTHRACITI'FEROUS  —  fr.  lat.  an 
thracite,  and  the  Lat.  fero,  I  bear. 
Containing  or  affording  anthra- 
cite. 

Apio'cRiifiTEs  —  fr.  gr.  apion.  a 
pear  ;  krinon,  lily.  The  pear  en- 
crinite  (p.  149).  A  sub-genus  of 
fossil  encri'nites,  in  which  the  stem 
is  rounded  and  dilated,  at  its  upper 
part,  into  a  pyriform  shape. 


GLOSSARY,  — GEOLOGY. 


213 


AQ.UA/TIC — fr.  lat.  aqua,  water.  Re- 
lating or  belonging  to  water. 

Ao.t'iLi'NA — Lat.  Of  or  like  an  eagle; 
rapacious. 

AHAUCA'RIA — (From  Arauco,  a  dis- 
trict of  Chile.)  Fir-trees  with  very 
rigid  branches,  having  leaves  like 
scales  either  small  and  sharp-point- 
ed, or  stiff,  spreading,  and  lanceo- 
late. The  Norfolk  island  pine  is 
one  of  this  genus. 

ARBORE'SCEXT — fr.  lat.  arbor,  a  tree. 
Branching  like  a  tree. 

AHCUA'TA — Lat.  Arched;  bent  like  a 
bow. 

AREXA'CEOUS —  fr.  lat.  arena,  sand. 
Sandy  ;  of  the  nature  of  sand. 

ARGIJ.  —  fr.  lat.  argil/a,  clay,  which 
is  formed  from  the  Greek  argos, 
white ;  because  when  pure  it  is 
white.  Old  name  of  alu'mina. 

ARGILLA'CEOUS — Of  the  nature  of 
clay. 

ARGILLA'CEOUS-SCHIST — Clay  slate, 
or  argillite. 

AR'GILLITE — A  slaty  rock  of  fine  tex- 
ture, with  a  faintly  glistening,  or 
earthy  surface  of  fracture,  and 
mostly  of  a  dark  colour.  Roofing 
slate,  and  nova'culite  or  hone-slate 
are  varieties  of  argillite. 

ARGILO-ARENA'CEOUS — Partaking  of 
the  nature  of  both  clay  and  sand. 

ARIETI'NA — Lat.  Belonging  or  re- 
lating to  a  ram. 

ARKOSE — A  name  given  to  different 
metamorphic  sandstones,  (p.  178.) 

ARTICULA'TION — fr.  lat.  articulus, 
a  joint.  A  joint  betwixt  bones. 

A'SAPHUS — fr.  gr.  asaphes,  obscure. 
A  name  devised  to  express  the  ob- 
scure nature  of  a  genus  of  trilobites, 
fossil  crustaceans — (p.  28.) 

ASBF/STUS,  or  ASBESTOS  —  fr.  gr. 
asbestos,  unconsumable.  A  fibrous 
soft  mineral,  composed  of  easily 
separable  filaments  of  a  silky  lustre. 
It  consists  essentially  of  si'lica,  mag- 
nesia and  lime. 

AST  A' RTF/ — Name  of  a  genus  of  fos- 
sil bivalve  shells.  (Figs.  104, 105, 
176.) 


ASTRE'A  —  fr.  gr.  aster,  a  star.  A 
genus  of  poly pa'ria.  (p.  141.) 

ASTKE';E — Plur.  of  Astrea. 

ATHLE'TA  —  Specific  name  of  mol- 
lusk. 

AU'GITE  —  fr.  gr.  auge,  lustre.  A 
mineral,  the  same  as  pyroxene. 

AU'GITIC-PORPHYRY  —  Crystals  of 
Labrador  feldspar,  and  of  augite  in 
a  green  or  dark-grey  base. 

AVALA'NCHE —  Mass  of  hardened 
snow,  detached  from  lofty  moun- 
tains, which  overturns  everything 
in  its  way,  often  causing  great  de- 
struction. Applied  also  to  slides 
of  earth  and  clay. 

AVI'CULA  —  fr.  lat.  avis,  a  bird. 
Name  of  a  genus  of  bivalve  mol- 
lusks.  (Figs.  63,  p.  52.) 

A'xis  OF  ELEVA'TION — Line  of  ele- 
vation. 

BAC'CILAR  —  fr.  lat.  bacca,  a  berry. 
Berry-like. 

BA'CULITES  —  fr.  lat.  bacculum,  a 
stick.  A  genus  of  tetrabranchiate 
cephalopods,  the  chambered  shells 
of  which  are  quite  straight,  but 
differ  from  those  of  the  orthocera- 
tites  in  having  sinuous  or  undu- 
lated partitions  with  lobated  1nar- 
gins  :  in  this  structure  they  are 
allied  to  the  Ammonites,  (p.  72.) 

BAG-SHOT  SAND.  A  siliceous  bed 
which  overlies  the  London  clay 
formation,  corresponding  in  age 
with  the  Paris  basin. 

BALA'NI — Plur.  of  balanus. 

BALA'NUS  —  Lat.  A  barnacle,  (p. 
85.) 

BALLOTS — Fr.  ballon,  a  ball.  Round- 
ed mountains  are  so  called.  A  sys- 
tem of  upheaval — p.  191. 

BARRA'NCO — Sp.    A  ravine. 

BASA'LT  —  A  rock  essentially  com- 
posed of  feldspar,  and  augite  of  a 
compact  texture,  and  dark  green, 
grey  or  black  colour.  It  occurs  in 
columnar  masses.  When  light-co- 
loured, with  the  feldspar  predomi- 
nating, it  is  sometimes  called  grey- 
stone.  Basalt  closely  resembles 
greenstone. 


214 


GLOSSARY.  — GEOLOGY. 


BASA'LTIC  —  Of  the  nature  of  ba- 
salt. 

BASSET  —  Outcrop,  or  emergence  of 
strata  at  the  surface. 

BASTERO'TI — Specific  name  of  a  fos- 
sil (p.  90). 

BATRA'CHIAIT  (Ba-trak'-ean}  —  fr. 
gr.  batrachos,  frog.  A  kind  of 
reptile  resembling  a  frog  in  its  mode 
of  organization. 

BELE'MNITES —  fr.  gr.  bekmnon,  a 
dart.  A  genus  of  fossil  dibranchiate 
cephalopods,  the  shells  of  which  are 
chambered  and  perforated  by  a  si- 
phon, but  internal.  They  are  long, 
straight,  and  conical ;  and  com- 
monly called  "  thunder  stones"  (p. 
55  and  74). 

BELLE'RAPHON.    p.  38  and  Jig.  33. 

B  ICORDA'TUS — Lat.  Bicordate ;  double 
heart-shaped. 

BI'FURCATED — fr.  lat.  bis,  two,furca, 
fork.  Divided  into  two  branches. 

BIOCULA'TA  —  fr.  lat.  bis,  two,  ocu- 
lus,  an  eye.  Two-eyed. 

BITU'MEN —  fr.  gr.  pitus,  the  pitch- 
tree  ;  because  it  resembles  pitch. 
A  variety  of  inflammable  mineral 
substances,,  which,  like  pitch,  is  in- 
cluded under  this  term. 

BITU'MENIZED —  Converted  into  bi- 
tu'men. 

BITU'MINOUS — Of  the  nature  of  bi- 
tumen. 

BITU'MISTOUS  SHALE — A  slaty  rock 
containing  bitumen. 

BI'VALVE —  fr.  lat.  bis,  two,  valvae, 
doors.  Shells  composed  of  two 
pieces  united  by  a  hinge  are  termed 
bivalves. 

BLENDE  —  Sulphuret  of  zinc,  a  com- 
mon shining  zinc  ore. 

BLUMENBA'CHII — The  name  of  Blu- 
menbach  latinized. 

BOSSE — French.  A  hillock  ;  a  round- 
ed projection  or  elevation. 

BOTHY'OIDAL — fr.  gr.  botrus,  a  bunch 
of  grapes,  and  eidos,  resemblance. 
Clustered  like  a  bunch  of  grapes; 
covered  with  smooth,  rounded 


BOULDER  FORMATION,     p.  93. 


BRAC'HIOPOD  (Bra'ke-o~pod.)  —  fr. 
gr.  brachion,  arm,  pous,  foot.  A 
mollusk  with  a  two-lobed  mantle 
and  bivalve  shell.  (See  Concho- 
logy,  p.  88.) 

BRACHY'PHY'LLUM —  fr.  gr.  brachus, 
short,  phullon,  leaf.  A  genus  of 
fossil  plants.  (Fig.  94,  p.  61.) 

BRADFORD  CLAY  —  An  English  bed 
of  the  great  o'olite,  usually  consist- 
ing of  a  pale  greyish  clay,  Contain- 
ing a  small  proportion  of  calcareous 
matter,  and  inclosing  thin  slabs 
of  tough  brownish  limestone.  It 
abounds  in  fossil  apiocrinites. 

BRASH  —  A  provincial  word  used  in 
England  to  describe  the  alluvial 
mass  or  quantity  of  broken  and 
angular  fragments  of  subjacent  rock, 
found  usually  between  the  vegeta- 
ble mould  and  the  regular  rocks. 
It  is  also  called  rubble. 

BRE'CCIA  (break' -co) — It.  A  rock 
composed  of  an  agglutination  of 
angular  fragments.  When  the  frag- 
ments are  rolled  pebbles,  it  consti- 
tutes a  conglomerate  rock  called 
pudding  stone. 

BREVIFO'LIA — Lat.  from  brevis,  short, 
folium,  leaf.  Short-leaved. 

BRONGXIARTII  —  Specific  name  of  a 
fossil  in  honour  of  M.  Brongniart, 
the  eminent  French  naturalist, 
(p.  60.) 

BUC'CINUM  —  Lat.  A  trumpet  or 
horn.  Name  of  a  genus  of  mol- 
lusks.  (p.  90.) 

BU'CHII — The  name  of  Von  Buch 
latinized. 

BUCKLA'JTDII — Specific  name  of  cer- 
tain fossils,  given  in  honour  of 
the  eminent  geologist  Dr.  Buck- 
land. 

BUPRE'STES — Lat.  Noxious  insects. 
Certain  beetles. 

CALA'MITES — fr.  gr.  kalamos,  a  reed. 
Common  fossil  plants  in  the  coal 
strata.  Cala'mites  usually  consist 
of  jointed  fragments  which  are  sup- 
posed to  be  portions  either  of  the 
trunk,  or  branches  of  a  plant,  which 
appears  from  some  of  the  larger 


GLOSSARY.  — GEOLOGY. 


215 


specimens,  to  have  attained  the 
dimensions  of  a  tree.  Both  stem 
and  branches  were  deeply  ribbed 
along  their  whole  length,  and  the 
ribs  or  furrows  were  crossed  by 
horizontal  rings  at  irregular  inter- 
vals (p.  42). 

CALC-SINTER — Ger.  sinlern,  to  drop. 
A  German  term  for  limestone  de- 
posited from  springs  and  waters 
containing  it.  Travertin. 

CALCA'IRE  GROSS'IER — Fr.  Marine 
limestone. 

CALCA'IRE  SILI'CEUX — Fr.  Fresh 
water  or  siliceous  limestone. 

CALCA'REOUS —  fr.  lat.  calx,  lime. 
Containing  lime. 

CALCAREOUS  GRITS — Sandy  beds,  in- 
termixed with  calcareous  matter, 
found  in  the  o'olite  (p.  62). 

CALCE'OLA  —  fr.  lat.  calceolous,  a 
little  shoe.  A  fossil  bivalve  shell 
(p.  33). 

CALCI'FEROUS —  fr.  lat.  calx,  lime, 
fero,  I  bear.  Containing  lime. 

CAI/CINED — fr.  lat.  calx,  lime.  Con- 
verted into  calx  or  a  friable  sub- 
stance by  the  action  of  fire. 

CALCINA'TION —  The  reduction  of 
bodies  to  a  calx  or  friable  condition 
by  the  action  of  fire. 

CAL'VUS — Lat.  Bald.  Specific  name 
of  a  productus. 

CALT'MEN  E  —  fr.  gr.  kekalumene, 
concealed.  A  name  of  a  genus  of 
trilobites  (p.  29). 

CAMBRIAX  SYSTEM — p.  27. 

CANUJEFO'RMIS  —Lat.  fr.  canna,  a 
reed,  formis,  form.  Reed-shaped 
(p.  42). 

CANIS — Lat.     Dog. 

CAR'BOX —  fr.  lat.  carbo,  a  coal. 
The  pure  inflammable  principle  of 
charcoal ;  in  its  state  of  absolute 
purity,  it  constitutes  the  diamond. 

CAR'BOSTATE —  A  compound  of  car- 
bonic acid  with  a  salifiable  base ; 
carbonate  of  lime,  for  example,  is 
a  compound  of  carbonic  acid  with 
lime,  constituting  chalk,  limestone, 
marble,  &r 


CARBON  A'CEOUS — Belonging  or  relat- 
ing to  carbon. 

CAR'BONIC  ACID  —  An  acid,  com- 
pounded of  carbon  and  oxygen. 

CAR'BONOUS — Of  the  nature  of  car- 
bon. 

CARBOXI'FEROUS —  fr.  lat.  carbo,  a 
coal,  fero,  I  bear.  Containing 
carbon. 

CAR'BOJT ISEB — Converted  into  carbon. 

CARBONTSA'TION  —  The  action  of 
forming  or  converting  a  substance 
into  carbon. 

CAR'BURET— A  combination  of  car- 
bon with  a  metal  or  other  sub- 
stance ;  steel  and  black  lead  are 
carburets  of  iron. 

CAR'BUHETTED —  Converted  into  a 
carburet ;  containing  carbon. 

CAR'DIUM — Lat.  A  cockle.  A  genus 
of  bivalve  shell  (p.  81). 

CARINA'TA — Lat.  from  carina,  a  keel. 
Carinate ;  having  a  keel-like  eleva- 
tion. 

CARJTI'VORA  —  Lat.  Carnivorous. 
Carni'vorous  animals. 

CARSTI'TOROUS  —  fr.  lat.  caro,  (geni- 
tive carra's,)  flesh,  voro,  I  eat. 
Flesh-eating. 

CA'RYOPHY'LLTA —  fr.  lat.  caryo'- 
phyllus,  the  garden  pink.  A  genus 
of  Ma'drepo'ra  (p.  141). 

CAS'CADE  —  fr.  fr.  A  cataract ;  a 
water-fall. 

CATE'NA — Lat.  A  chain.  Specific 
name  of  an  ammonite  (p.  152). 

CA'TENATED — fr.  lat.  catena,  a  chain. 
Linked  together. 

CATEXIPO'RA  —  fr.  lat.  catena,  a 
chain,  pora,  pore.  Generic  name 
of  a  polyp  (p.  31). 

CA'TYIUS  or  CATILLUS —  Lat.  A 
little  dish.  A  genus  of  fossil  shells 
(p.  74). 

CAUDA'TUS — Lat.  Caudate  ;  having 
a  tail. 

CAVE'RSTOUS  —  fr.  lat.  cavus,  a  hol- 
low. Containing  hollows;  exca- 
vated. 

CE'METTTED — Joined  together  by  ce- 
ment. 


216 


G  L  0  S  S  A  R  Y.  —  G  E  O  L  0  G  Y. 


CEMENTA'TIOX — When  a  solid  body 
is  surrounded  by  the  powder  of 
other  substances,  and  the  whole 
heated  to  redness,  the  process  is 
termed  cementation.  Iron  is  con- 
verted into  steel  by  cementation 
with  charcoal. 

CENTIGRADE  (Thermometer)  —  fr. 
lat.  centum,  hundred,  gradus,  a 
degree.  Division  into  a  hundred 
parts.  The  scale  of  the  centigrade 
thermometer  is  made  by  dividing 
the  space  between  the  points  of 
freezing,  and  boiling  water,  into 
one  hundred  parts  or  degrees. 
CEPHALA'SPIS  (kej-al a'spifi) —  fr.  gr. 
keplialc,  head,  aspis,  shield.  A 
genus  of  fossil  fishes  (p.  37). 
CE'PHALOPOD  (kt'f  alu-pod)  —  fr.  gr. 
kephale,  head,  pous,  in  genitive 
case  podos,  foot.  A  mollusk  which 
has  the  head  situated  between  the 
body  and  feet. 

CERI'THIA — Plur.  of  cerithium. 
CERI'THIUM — A  genus  of  turriculated 
univalve  mollusks,  both  recent  and 
fossil  (p.  80  and  151). 
CE'ROID  —  fr.  gr.  keros,  wax,  eidos, 

resemblance.     Wax-like. 
CESTRA'CION — French,    fr.  gr.  kes- 
traios,  name  of  a  fish.     A  genus 
of  the  family  of  sharks  (p.  45). 
CETA'CEA  —  Lat.    fr.    gr.    kelos,    a 
whale.    Name  of  an  order  of  mam- 
mals. 

CETA'CEJE — Plur.  of  ceta'cea. 
CETA'CEOUS —  Relating  or  belonging 

to  ceta'cea. 

CHALCE'DONY  —  fr.  gr.  kalkedon, 
Chalcedon,  in  Asia,  where  the 
finest  specimens  were  originally 
found.  A  semi-transparent  siliceous 
mineral,  apparently  found  by  the 
infiltration  of  siliceous  matters  in  a 
state  of  solution.  The  chalcedo'nic 
varieties  of  quartz  include  Chalce- 
dony, Crysoprase,  Cornelian,  Sard, 
Agate,  Onyx,  Cat' s-eye,  Flint,  and 
Hornstone. 

CHALK  —  fr.  ger.  kalk.  Earthy  car- 
bonate of  lime.  Chalk  has  been 
discovered,  it  is  said,  for  the  first 


time  in  the  United  States,  in  Ala- 
bama, 1845. 

CHALK  MARL  —  Marl  belonging  to 
the  cretaceous  formation. 

CHA'MA  (ka-ma~) —  fr.  gr.  chad,  I 
gape.  A  cockle  (p.  67  and  151). 

CHA'RA — (Origin  of  this  word  is  un- 
known.) A  genus  of  aquatic 
plants. 

CHELO'NTANS —  fr,  gr.  chelone,  a  sea- 
tortoise.  Animals  of  the  tortoise 
tribe. 

CHERT  —  A  siliceous  mineral  resem- 
bling flint.  It  is  usually  found  in 
limestone. 

CHLO'RITE  —  fr.  gr.  chloros,  green. 
A  soft,  green,  scaly  mineral,  slight- 
ly unctuous. 

CHLO'HITIC  CHALK — Chalk  contain- 
ing chlorite. 

CHLO'RITIC  SCHIST — Schist  contain- 
ing chlorite. 

CHROME  —  fr.  gr.  chroma,  colour. 
The  oxide  of  a  rnetal  called  chro- 
mium. Oxide  of  Chrome  is  green 
and  furnishes  a  valuable  colour  for 
porcelain. 

CHROXO'LOGY — fr.  gr.  chronos,  time, 
logos,  discourse.  The  science  which 
treats  of  the  divisions  of  time,  and 
the  order  and  succession  of  events. 

CICA'TRICES — Plur.  of  cica'trix. 

CICA'TRIX — Lat.     A  scar. 

CIHA'RIS  —  Lat.  A  cap  or  turban. 
Name  of  a  genus  of  Echini'dese 
(p.  150). 

CINDERS  —  Matters  remaining  after 
combustion. 

CLAVELLA'TA  —  Lat.  (fr.  claiming,  a 
little  nail.)  Marked  by  little  pro- 
jections or  points ;  knotted. 

CLEAVAGE — The  mechanical  divi- 
sion, the  laminae  of  rocks  and  mine- 
rals, to  show  the  constant  direc- 
tion in  which  they  may  be  sepa- 
rated. 

CLIXKSTOSTE — See  pho'nolite. 

CLTME'NIA  —  fr.  gr.  klumenon,  the 
marigold  ?  A  genus  of  fossil  cepha- 
lopods  of  the  Devonian  system  (p. 
33),  with  a  chambered  shell  ana 
logous  to  that  of  the  ammonite. 


GLOSSARY.  — GEOLOGY. 


217 


COAL  MEASURES — The  formations  in 
which  coal  is  found. 

COCCINELLOIDES —  fr.  lat.  and  gr. 
coccinella,  cochineal,  eidos,  resem- 
blance. Resembling  the  cochineal 
insect. 

COCCO'STEUS  —  Name  of  a  genus  of 
fossil  fishes  (p.  32). 

COLEO'PTERA  —  fr.  gr.  koleos,  sheath, 
pferon,  wing.  Name  of  an  order 
of  insects. 

COLU'MBA — Lat.  A  dove.  Specific 
name  of  a  fossil-shell. 

COLUMNA'RE — Lat.  Columnar.  In 
form  of  a  column. 

COMING  TO  DAY — When  a  vein  or 
stratum  crops  out  or  appears  on  the 
surface  it  is  said  to  come  to  the 
day. 

COMMINUTED — Fractured  into  small 
pieces. 

COMMU'NIS-E — Lat.    Common. 

COMPARATIVE  ANATOMY — The  com- 
parative study  of  the  various  parts 
of  the  bodies  of  different  animals. 

COMPTO'NIA —  A  genus  of  plants 
named  in  honour  of  Henry  Comp- 
ton,  Lord  Bishop  of  London  (p.  88). 

CONCE'NTRIC —  Having  a  common 
centre. 

CONCE'NTRICUS — Lat.     Concentric. 

CONCUI'FEROUS  (con-kif-erous)  —  fr. 
lat.  concha,  shell,  fero,  I  bear. 
Shell-bearing. 

CONCHY'LIAN  (con-kit '-eari) — Con- 
sisting of  or  containing  shells. 

CONCRE'TIONARY  FORMATION — (p. 
183). 

CONDE'NSABLE  GAS — Any  gas  that  is 
susceptible  of  being  condensed  into 
a  fluid,  or  solid. 

Cox DUIT — A  water-pipe ;  a  canal. 

CONE    OF    ELEVATION (p.   107). 

CONFORMABLE  STRATIFICATION  — 
When  the  strata  are  parallel  to 
each  other  (p.  185). 

CO'NGENERS —  fr.  lat.  con,  with,  ge- 
nus, race.  Species  belonging  to 
the  same  genus. 

CONGLOMERATE  —  fr.  lat.  conglo- 
mero,  I  heap  together.  A  rock 
composed  of  pebbles  cemented  to- 
19 


gether  by  another  mineral  sub- 
stance, either  calcareous,  siliceous, 
or  argilla'ceous. 

CO'NICA — Lat.     Conical. 

CO'NIFER  —  fr.  lat.  conus,  a  cone, 
fero,  I  bear.  A  tree  or  plant  which 
bears  cones,  such  as  pines,  fir-trees, 
&c. 

CONOIDEA  —  Lat.  Conoidal.  Cone- 
shaped. 

CONOID AL  —  fr.  lat.  conus,  a  cone, 
and  the  Gr.  eidos,  resemblance. 
Cone-shaped  ;  like  a  cone. 

CONTEMPORANEOUS  —  fr.  lat.  con, 
with,  tempus,  time.  Existing  at 
the  same  time. 

CONTO'RTED — fr.  lat.  con,  together, 
torqueo,  I  twist.  Twisted  together ; 
bent. 

CO'PROLITES  —  fr.  gr.  kopros,  dung, 
lithos,  stone.  Fossil  excrement 
(p.  44). 

CORAL  —  fr.  gr.  koreo,  I  ornament, 
als,  the  sea.  The  hard  calcareous 
support  formed  by  certain  polypi. 

CORAL  RAG  —  Certain  beds  of  the 
middle  o'olite,  consisting  chiefly  of 
corals  (p.  63). 

COH'ALLINE  —  Belonging  or  relating 
to  coral. 

CORALLOI'DES  —  Lat.  from  coral  and 
the  Gr.  eidos,  resemblance.  Coral- 
like.  Specific  name  of  a  devonian 
fossil  (p.  33). 

COR-AN'GUINUM — Lat.  cor,  heart,  an- 
guinum,  snake-like.  Specific  name 
of  a  fossil  (p.  75). 

CORNBRASH  —  An  o'olitic  bed  con- 
sisting of  clays  and  sandstones.  Its 
name  is  probably  derived  from  the 
excellence  of  the  corn-land,  which 
results  from  the  decomposition  of 
the  limestones,  and  their  mixture 
with  the  sandstones  and  clay. 

CORNU'TUS — Lat.     Horned. 

CORONA'TA — Lat.     Crowned. 

COSTA'TUS — Lat.     Ribbed. 

CRAG  FORMATION — (p.  84). 

CRASSATE'LLA  —  A  genus  of  bivalve 
shells. 

CRA'SUS— Lat.     Thick. 

CHA'TER  —  fr.   lat.   crater,    a    great 


218 


GLOSSARY.  — GEOLOGY. 


cup  or  bowl.  The  mouth  of  a  vol- 
cano (p.  107). 

CRA'TER  OF  ELEVATION — (p.  107). 

CRATE'RIFORM — In  form  of  a  crater. 

GRENA'TUM — Lat.  Crenate  ;  having 
rounded  teeth. 

CRETA'CEOUS —  ft.  lat.  creta,  chalk. 
Of  the  nature  of  chalk ;  relating  to 
chalk. 

CRINOIBEJB  —  fr.  gr.  krinon,  lily, 
eidos,  resemblance.  A  family  of 
radiate  animals. 

CRIOCE'RATITES  —  fr.  gr.  krios,  a 
ram,  and  keras,  a  horn.  A  fossil 
cephalopod  (p.  67). 

CHI'SES — Plur.  of  crisis. 

CRI'SIS  —  Gr.  The  point  of  time 
when  any  affair  comes  to  its  height. 

CROCODI'LIAN  —  Any  animal  of  the 
tribe  of  crocodiles. 

CROP  OUT — When  a  rock,  in  place, 
emerges  on  the  surface  of  the  earth, 
it  is  said  to  crop  out. 

CRUSTA'CEAN —  Any  animal  of  the 
class  of  crusta'cea ;  a  crab. 

CRYPTOGA'MIA — fr.  gr.  kruptos,  con- 
cealed, games,  marriage.  Name  of 
a  class  of  plants. 

CRY'STAL  —  fr.  gr.  krustallos,  ice. 
This  term  was  originally  applied 
to  those  beautiful  transparent  varie- 
ties of  si'lica,  or  quartz,  known  un- 
der the  name  of  rock-crystal.  When 
substances  pass  from  the  fluid  to 
the  solid  state,  they  frequently  as- 
sume those  regular  forms  which 
are  generally  termed  crystals.  A 
crystal  is  any  inorganic  solid  of 
homogeneous  structure,  bounded  by 
natural  planes  and  right  lines  sym- 
metrically arranged. 

CRY'STALLINE  —  Relating  to,  or  re- 
sembling crystals. 

CRYSTALLISA'TION — The  process  of 
forming  crystals. 

CTENOIDEANS  —  fr.  gr.  kteis,  in  the 
genitive,  ktenos,  a  comb.  An  order 
of  fishes  (p.  48). 

CUCTTLLA'TUS — Lat.     Hooded. 

CUPROUS — Belonging  to  copper. 

CUVIERI — The  name  of  Cuvier  la- 
tinized. 


CY'ATHOCRI'NITES —  fr.  gr,  Jcuathos, 
a  cup,  krinon,  lily.  A  genus  of 
crinoideae  (p.  33.) 

CY'ATHOFHYLLA  —  Plur.  cyathophyl- 
lum. 

CT'ATHOPHTLLUM  —  fr.  gr.  huathos, 
a  cup,  phullon,  a  flower.  A  genus 
of  polypa'ria  (p,  31). 

CTCA'DE^E — (From  cycas,  one  of  the 
genera.)  An  order  of  plants. 

CY'CAS  —  A  name  employed  by  the 
ancients  to  designate  a  little  palm. 
(Fig.  306,  p.  196.) 

CY'CLABES — Plur.  of  cyclas. 

CY'CLAS  —  fr.  gr.  kuklos,  a  circle.  A 
genus  of  gasteropods. 

CYCLOJDEANS  —  fr.  gr.  kuklos,  a  cir- 
cle. An  order  of  fishes  (p.  49). 

CY'MJBIUM  —  fr.  gr.  kumba,  a  boat, 
specific  name  of  a  shell. 

CY'PREA  —  fr.  gr.  kupris,  Venus.  A 
genus  of  gasteropod  mollusks. 

CY'PRIS —  fr.  gr.  kupris,  Venus. 
Name  of  a  genus  of  crusta- 
ceans. 

CYRE'NA —  A  genus  of  bivalve  mol- 
lusks. 

DA'TA  —  fr.  lat.  datum,  given,  a  gift. 
Admitted  facts. 

DEBACLE  —  Fr.  Sudden  escape  of 
water  from  a  lake,  following  a 
bursting  of  its  barrier  (p.  128). 

DE'BRIS  (de'-bree)  —  Fr.  Wreck, 
ruins,  remains  (p.  14). 

DEFRA'NCII  — The  name  of  Defrance 
latinized  (p.  74). 

DEGRADE  —  fr.  lat.  de,  privitive,  gra- 
dus,  step,  degree.  To  lessen,  to 
cut  down. 

DEGRADATION — The  act  of  lessen- 
ing ;  reduction. 

DEJECTIONS — Matters  evacuated  from 
the  bowels. 

DELTA— (p.  16  and  134). 

DELTOIDEA  —  Lat.  fr.  gr.  letter  A, 
eidos,  resemblance.  Resembling  a 
delta  A  (p.  65). 

DENTA'TUM — Lat.  Dentate  ;  having 
sharp  teeth. 

DENUDE  —  fr.  lat.  denudo,  I  strip. 
To  lay  bare. 

DENUDA'TION — A  removal  of  a  part 


GLOSSARY,  — GEOLOGY. 


219 


of  the  land,  so  as  to  lay  bare  the 
inferior  strata. 

DEPOSITION —  fr.  lat.  depono,  I  let 
fall.  The  falling  to  the  bottom  of 
matters  suspended  or  dissolved  in 
water  or  other  liquid. 

DEPRE'SSUS — Lat.     Pressed,  sunk. 

DECS — Lat.     God. 

DEVONIAN  SYSTEM — (p.  32). 

DIADE'MA — Lat,  A  diadem,  a  crown, 
A  genus  of  echini'deae  (p.  54). 

DI'AGRAM — fr.  gr.  diet,  through,  gra- 
phb,  I  write.  A  figure  drawn  for 
illustration. 

DIA'LLAGE —  fr.  gr.  diallage,  differ- 
ence. A  mineral  of  foliated  struc- 
ture easrly  divisible  in  one  direction, 
its  natural  joints  and  fractures  ex- 
hibiting a  very  different  lustre  and 
appearance. 

DICE' HAS  —  fr.  gr.  dis,  two,  keras, 
horn.  Generic  name  of  a  fossil  bi- 
valve (p.  64,  fig.  106). 

DICOTY'LEDONS  —  fr.  gr.  dis,  two, 
kotuledon,  seed-lobe.  A  division  of 
plants,  according  to  the  Natural 
Order. 

DICOTTLE'BONOUS — Relating  to  dico- 
tyledons, 

DIGO'NA —  fr.  gr.  dis,  two,  gone, 
angle.  Having  two  angles, 

DTLATA'TA  —  Lat.  Dilated,  swelled 
out. 

DILU'VIAL — Relating  to  dilu'vium. 

DILU'YIOX,  }  fr.  lat  diluo,   I    wash 

DiLuViUM,  5  away.  A  superficial 
deposit  (p.  92). 

DINOTHE'RIUM —  fr.  gr.  dinos,  cir- 
cular, therion,  a  beast  (p.  86). 

DI'OIUTE  —  A  variety  of  trap  rock 
consisting  of  albite  and  hornblende. 

DIP— ^Direction  of  the  inclination  of 
strata.  "  To  take  a  dip,"  is  to  mea- 
sure the  degree  that  a  stratum  in- 
clines or  dips  from  a  horizontal  line 
(p.  185). 

DIRECTION  OF  STRATA — The  Strike, 
or  line  of  bearing  (p.  185). 

DIRT-BED — (Portland)  p.  145. 

DISAGGREGATED  —  fr.  lat.  de,  pri- 
vitive,  aggrego,  I  gather  together. 
Separated,  divided,  broken  up. 


DISAGGREBA'TION — The  breaking  up 
of  a  mass  into  small  parts. 

DlSCORDAKT    STRATIFICATION Un- 

conformable  stratification. 

DISENGAGED — Separated  from,  freed. 

DISINTEGRATE  —  fr.  lat.  de,  privi- 
tive,  integer,  entire,  whole.  To 
separate  or  break  up  an  aggregate 
into  parts. 

DISINTEGRATION — The  act  of  separ- 
ating or  dividing  a  whole  into  parts. 

DISLOCATE  —  fr,  lat.  de,  privitive,  lo- 
cus, place.  To  put  out  of  place. 

DISLOCATION  —  Displacement  of  a 
part. 

DISPOSITION  —  fr.  lat  dispono,  I 
arrange.  Arrangement,  method, 
order. 

DISRUPTION  —  fr.  lat  disrumpo,  I 
break  off.  The  act  of  breaking 
asunder. 

DISTORTION  —  fr.  lat.  de,  from,  tor- 
turn,  twisted.  The  act  of  distorting 
or  twisting  out  of  place. 

DOLICHODE'IRUS  (doli-lco-dy-rus]  — 
Lat  fr.  gr.  dolichos,  long,  deire, 
neck.  Long-necked  (p.  57). 

DO'LOMITE — Named  after  Dolomieu. 
Magnesian  marble:  granular  mag- 
nesian  carbonate  of  lime.  It  con- 
tains about  45  per  cent  of  carbo- 
nate of  magnesia.  It  is  commonly 
more  friable  or  crumbling  than  pure 
limestone,  and  less  durable  as  a 
building  material. 

DOLGMISA'TIOJT — The  conversion  of 
common  into  magnesian  limestone 
or  dolomite  (p.  170). 

DOME  —  fr.  lat.  domus,  house,  A 
rounded  projection. 

DO'XITE — A  tra'chytic  rock  (p.  171). 

DRIFT— (p.  92). 

DUNES— Fr.  Downs  (p.  124). 

DUVALII — Name  of  Duval  latinised. 

DYKE  or  DIKI— (p.  118). 

EAKTHQ.UAKES — (p.  97). 

EBULU'TION — The  act  of  boiling. 

ECHI'NIDJE    £  fr.     gr.     echinos,     a 

ECHINI'DEJB  5  hedge-hog,  eidos,  re- 
semblance. Systematic  name  of  the 
order  of  sea-urchins. 

Ecm'>*ojDEaMs  —  fr.  gr.    echinos,    a 


220 


GLOSSARY.  — GEOLOGY. 


hedge-hog,  derma,  skin.  A  class 
of  invertebrate  animals,  with  a  crus- 
ta'ceous  integument  armed  with  tu- 
bercles or  spines  (p.  52). 

EDENTA'TA  —  Edentate.  An  order 
of  mammals  without  teeth. 

EDE'NTATE — fr.  lat.  e,  without,  dens, 
tooth.  Without  teeth. 

EFFERVE'SCEITCE  —  fr.  lat.  effervesco, 
I  grow  hot.  The  commotion  pro- 
duced in  fluids  by  the  sudden  escape 
of  gas  in  the  form  of  bubbles.^ 

EFFU'SION  —  fr.  lat.  effundo,  I  pour 
out.  The  pouring  out  of  a  liquid. 

E'LEGANS — Lat.     Elegant. 

EMBOSS  —  fr.  fr.  bo&se,  a  protuber- 
ance. To  cover  with  lumps  or 
bunches. 

ENCRI'NITES  —  fr.  gr.  krinon,  a  lily. 
A  genus  of  echi'noderms  (p.  52). 

E'NTOMO'STRACANS  —  fr.  gr.  ento- 
mos,  incised,  ostrakon,  a  shell.  A 
division  of  the  class  of  crust a'cea. 

E'OCE'NE— (p.  78). 

EPIDEMIC  —  fr.  gr.  epi,  upon,  de- 
mos, the  people.  A  prevailing  dis- 


E'pocH — The  time  from  which  dates 
are  numbered. 

E'POCH    OF    FORMATION (p.  192). 

EQ.UA'I-IS — Lat.     Equal. 
EatrA'TioN — fr.  lat.  sequare,  to  equal. 

Equivalent.     A  mean   proportion 

between  extremes. 

Eauin'BRiUM — fr.  lat.  segue,  equal- 
ly, libra,  I  balance.    Equal  balance. 
EQ.UISE'TA — Plur.  equisetum. 
EOTTISETA'CE^ —  fr.  equise'tttm,  one 

of  the  genera.     A  natural  order  of 

plants. 
EQ.UISE'TUM  —  fr.  lat.  eguus,  horse, 

seta,  hair.     A  genus  of  plants. 
ERO'DE  —  fr.  lat.  erodo,  I  gnaw.     To 

wear  away,  to  corrode. 
ERO'SION — The  act  of  wearing  away. 
ERO'SIVE — Corroding,  wearing. 
ERRATIC    BLOCK   FORMATION  —  (p. 

93). 
ERU'PTIOST  —  fr.  lat.  e,  from,  rumpo, 

I  burst.     The  act  of  bursting  from 

any  confinement. 
ESCA'BPMJENT —  fr.  it.  scarpa,  sharp, 


formed  fr.  lat.  carpere,  to  cut  or 
divide.  The  steep  face  often  pre- 
sented by  the  abrupt  termination  of 
strata  where  subjacent  beds  "  crop 
out"  from  under  them. 

ESCHAROIDES  —  fr.  gr.  eschoro,  a 
fire-place,  a  gridiron,  eidos,  resem- 
blance. Specific  name  of  a  coral 
(p.  31). 

EUOM'PHALTJS — (p.  39). 

EU'PHOTIDE — A  rock  composed  essen- 
tially of  feldspar  and  diallage. 

EVOLU'TTJS — Lat.     Unfolded. 

EXCORIA'TION —  fr.  lat.  ex,  from, 
curium,  skin.  An  abrasion,  mark 
of  a  part  having  been  rubbed  from 
the  surface. 

EXO'GYBA —  fr.  gr.  exo,  without,  gu- 
ros,  circle.  Not  circular.  (Figs. 
109,  115,  125,  135.)  A  genus  of 
unimuscular  bivalves,  allied  to  the 
oyster. 

EXPLOSION — A  sudden  bursting  with 
noise  and  violence. 

EXTREMITIES  —  The  limbs  ;  legs, 
arms,  &c. 

EXUDA'TIOST  —  fr.  lat.  ex,  from,  sudoy 
I  sweat.  Transpiration. 

Exu'vi-E — Lat.  The  sloughs  or  cast- 
skins,  or  shells  of  animals. 

FASCI'CUI.IS — Lat.  Plur.of  fasciculus. 

FASCI'CUI.US — Lat.     A  bundle. 

FASTIGIA'TA — Lat.  Sharpened  at  top 
like  a  pyramid. 

FATHOM — A  measure  of  six  feet. 

FAULT  —  fr.  ger.  fall,  an  accident, 
sinking,  fall  (p.  158). 

FAU'NA  —  fr.  lat.  faunus,  the  name 
of  a  rural  deity  among  the  Romans. 
All  animals  of  all  kinds  peculiar  to 
a  country  constitute  the  fauna  of 
that  country. 

FECIT — Lat.    He  made. 

FELD'SPAR,  OR  FELSPAR  —  fr.  ger. 
feldspath.  An  important  mineral 
composed  of  si'lica,  alu'mina,  and 
potash,  with  traces  of  lime,  and 
often  of  oxide  of  iron.  It  enters 
into  the  composition  of  granite. 

FELDSPA'THIC — Of  the  naturetor  be- 
longing to  feldspar. 

FELIS — Lat.     A  cat. 


GLOSSARY.  — GEOLOGY. 


Specific  name  of  a  fossil 
zamia  (p.  65). 

FEHRTJ'GIKOUS — fr.  lat/errwm,  iron. 
Containing  iron. 

FICOI'DES —  fr.  lat  flcus,  a  fig-tree, 
and  gr.  eidos,  resemblance.  Speci- 
fic name  of  a  fossil  plant 

FIRMAMK'XTUM —  Lat.  The  firma- 
ment. 

FIS'SILE  —  fr,  lat  flndo,  I  split. 
Easily  split 

FIS'SURE — A  crack,  a  separation  ;  a 
split 

FLO'RA —  fr.  lat  flora,  goddess  of 
flowers.  All  the  plants  of  all  kinds 
of  a  country  constitute  the  flora,  of 
that  country. 

FLU'VIATILE — Belonging  or  relating 
to  a  river. 

FOLIA'CEA — Lat.     Foliated. 

FOLIA'TED —  fr.  lat  folium,  a  leaf. 
In  form  of  leaves ;  leafy. 

FORAMISTI'FERA  —  fr.  lat.  foramen, 
hole,yero,  I  bear.  Name  of  a  tribe 
of  minute  shells. 

FORMA'TIOK —  Any  group  of  rocks 
formed  during  a  particular  epoch, 
or  of  common  origin. 

Fos'sii,  —  fr.  [at.fodio,  I  dig.  Any 
organic  body,  or  the  traces  of  anjr 
organic  body,  whether  animal  or 
vegetable,  which  has  been  buried 
in  the  earth  by  natural  causes 
(p.  21). 

FOSSILI'FEROUS — Containing  fossils. 

FOS'SILIZED —  Converted  into  a  fos- 
sil. 

FU'LCRUM —  Lat.  A  prop.  The 
fixed  point  on  which  a  lever  moves. 

FUM'AHOLE — Fr.  Subterraneous  emis- 
sion of  hydrogen  gas  in  consequence 
of  the  ebullition  of  certain  sulphu- 
rous waters.  The  hole  or  orifice 
through  which  the  gas  escapes. 

FUMES — Vapours. 

FUSION — The  act  of  melting  ^  state 
of  fusion,  is  being  melted. 

FU'SIFORHE' — Lat  Fusimorm,  spin- 
dle-shaped. 

GALE'XA —  fr.  gr.   galene,    lead-ore. 
Sulphuret  of  lead,  that  is  a  com- 
pound of  sulphur  and  lead. 
19* 


GANOIDEAXS  —  An  order  of  fishes 
(p.  48). 

GA'RNET —  A  mineral  consisting  of 
silicates  of  alu'mina,  lime,  iron,  and 
manganese.  There  are  several  va- 
rieties of  this  mineral.  Garnet  oc- 
curs imbedded  in  mica  slate,  granite, 
and  gneiss,  and  occasionally  in 
limestone,  chlorite  slate,  serpentine, 
and  lava. 

GAS  —  fr,  ger.  geist,  spirit.  The 
name  given  to  all  permanently  elas- 
tic fluids  or  airs  different  from  the 
atmospheric  air. 

GA'SEOUS — Of  the  nature  of  gas. 

GAULT — A  kind  of  clay  (p.  71), 

GELA'TIITOUS — Jelly-like. 

GE'X  ERA — Lat     Plur.  of  genus. 

GENE'RIC — Relating  to  genus. 

GE'UUS  —  Lat.  A  kindred,  breed, 
race  or  family. 

GE'ODES  —  fr.  gr,  geodes,  earthy. 
Nodules  of  iron  stone,  hollow  in 
the  centre.  Rounded  pebbles  hav- 
ing an  internal  cavity,  lined  with 
crystals,  are  also  so  called. 

GE'OGENT  —  fr,  gr,  ge,  the  earth,  gei- 
nomai,  I  beget.  Science  embracing 
the  theories  of  the  formation  of  the 
entire  universe. 

GEOGNO'STIC — Relating  to  geognosy. 

GEOG'NOSY —  fr.  gr.  ge,  the  earth, 
gnosis,  knowledge.  Knowledge  of 
the  mineral  substances  which  con- 
stitute the  mountains  and  strata  of 
the  earth. 

GEOLO'GICAL — Relating  to  geology. 

GE'OLOGIST — One  skilled  in  geology. 

GE'OLOGT  —  fr.  gr.  ge,  the  earth,  lo- 
gos, discourse.  That  branch  of 
natural  history,  which  treats  of  the 
structure  of  the  terrestrial  globe.  It 
is  divided  into  descriptive  geology? 
dyna'mic  geology,  which  treats  of 
the  forces  by  which  the  surface  of 
the  earth  has  been  modified  ;  prac- 
tical and  economic  geology,  em- 
bracing the  application  of  geological 
science  to  mining,  road-making, 
architecture,  and  agriculture. 

GEY'SERS — From  an  Icelandic  word 
signifying  raging  or  roaring.  Cele- 


222 


GLOSSARY.  — GEOLOGY. 


brated  spouting  fountains  of  boiling 
water  in  Iceland  (p.  136). 

GIBBO'SITY  —  fr.  lat.  gibba,  a  bunch. 
A  protuberance. 

GIGA'NTEUM 


GLABER — Lat.     Smooth,  bald,  bare. 

GIA'CIERS —  Fr.  Masses  or  beds  of 
ice  formed  in  high  mountains,  de- 
rived from  the  snows  or  lakes  frozen 
by  the  continued  cold  of  those  re- 
gions (p.  150). 

GLOBA'TA.  —  Lat.   Globate,  rounded. 

GNEISS  —  Ger.  A  rock  resembling 
«  granite  in  its  constitution  and  ge- 
neral characters ;  but  it  contains 
more  mica  and  the  colours  are 
banded,  but  owing  to  the  arrange- 
ment of  the  minerals,  especially  the 
mica,  in  parallel  planes.  In  con- 
sequence of  this  structure  the  rock 
splits  into  coarse  slabs,  along  the 
planes  of  the  mica,  besides  having 
the  cross  fracture  or  cleavage  of 
granite.  It  is  often  described  as  a 
stratified  or  stratiform  granite.  A 
rock  intermediate  between  granite 
and  gneiss  is  called  gneissoid  gra- 
nite. Gneiss  is  used  for  building 
and  flagging"  (p.  25). 

GON'IATITES  (p.  38). 

GOODHALLII  —  The  name  Goodhall 
latinized. 

GRA'LLEJE  —  Lat.    Wading-birds. 

GRA'NITE —  A  crystalline  aggregate 
of  quartz,  feldspar,  and  mica.  The 
ingredients  of  granite  vary  in 
their  proportions,  and  the  rock  is 
described  as  mica'ceous,  feldspathic 
or  quartzose,  according  as  mica, 
feldspar,  or  quartz  is  the,  predo- 
minating mineral.  It  is  called  Por- 
phyritic  granite  when  the  feldspar 
is  uniformly  disseminated  in  large 
crystals ;  they  appear  like  white 
blotches,  often  of  a  rectangular 
shape,  over  a  worn  surface  of  the 
rock. 

GHANI'TIC — Belonging  or  relating  to 
granite. 

GRA'NTJLAR — Consisting  of  grains. 

GKA'PHITE  —  fr.  gr.  grapho,  I  write. 


A  mineral  composed  of  carbon  and1 
iron,  constituting  carburet  of  iron. 
It  is  known  as  plumbago  and  black 
lead,-  it  is  used  in  the  manufac- 
ture of  lead-pencils. 

GRAU'WACKE,  and  GRATWACKE  — 
Ger.  Grey  rock.  A  name  given 
to  some  of  the  older  shales  in  the 
geological  series,  and  also  to  the 
sandstones  that  accompany  them. 

GRA'VEL — Small  rounded  stones  vary- 
ing in  size  from  a  small  pea  to  a 
walnut,  or  something  larger. 

GRAVITATE  — -  fr.  lat.  grams,  heavy, 
To  tend  towards  the  centre  of  the 
earth,  as  ail  bodies  do  from  their 
weight. 

GREENSAND — A  formation  of  the  cre- 
ta'ceous  group  (p.  70). 

GREENSTONE  —  A  tough  variety  of 
trap-rock,  consisting  chiefly  of  horn- 
blende. 

GRE'S  BIGARRE' — Fr.  A  fine-grained 
solid  sandstone,  sometimes  white, 
but  more  frequently  of  a  red,  blue, 
or  greenish  colour.  It  is  the  same 
as  bunter  sandstein. 

GRIT — A  coarse-grained  sandstone. 

GRUNDSTEIN  —  Ger.  Greenstone  or 
diorite. 

GRY'PHEA — fr.  gr.  grupos,  incurved. 
A  genus  of  fossil  bivalves. 

GRT'PHITES  —  Generic  synonym  of 
the  productus  aculeatus  (p.  49). 

GRY'PHITE  LIMESTONE — A  marl,  so 
called  from  containing  gry'phea. 

GRY'PHITENKAIK  —  Ger.  A  name 
sometimes  given  to  zechstein  (p.  49). 

GYMNOSPE'RMOUS  —  fr.  gr.  gurnnos, 
naked,  sperma,  seed.  Having  naked 
seeds. 

GY'PSEOUS — Of  the  nature  of  gypsum. 

GT'PSUM  (jVp-suw).  —  Native  sul- 
phate of  lime.  The  transparent 
varieties  constitute  se/enite,  and  the 
fine  massive  Alabaster.  Gy'psum 
is  converted  into  plaster  of  Paris  by 
heat. 

KA'MITES  —  fr.  lat.  hamus,  a  hook. 
A  genus  of  extinct  cephalopods, 
inhabiting  chambered  shells,  losing 
their  spiral  form  after  their  com- 


GLOSSARY.  —  GEOLOGY. 


223 


mencement,  and  then  continued  for 
a  considerable  extent  with  a  single 
bend  on  themselves  like  a  hook. 
They  are  found  in  the  greensand 
of  England. 

HE'LICES — Plur.  of  helix. 

HE'LIX — Lat.    A  snail. 

HE'TEROCERCAL  —  fr.  gr.  'eteros,  op- 
posite, kerkos,  a  tail.  Having  the 
spine  prolonged  into  the  tail  (p.  49). 

HETERO'PHTLLA  —  fr.  gr.  'eteros,  op- 
posite, phullon,  leaf.  Specific  name 
of  a  fossil  plant  (p.  53). 

HIBBERTI  —  Name  of  Hibbert  la- 
tinized. 

HIEROGLY'PHICS-— fr.  gr.  ieros,  sa- 
cred, gluphd,  I  write.  Sculpture 
or  scripture  writing. 

HI'PPUHITES — fr.  gr.  ippouris,  horse- 
tail :  a  certain  fish.  A  genus  of 
extinct  mollusks,  supposed  to  be 
bivalve.  The  principal  valve  is  of 
a  sub-cylindrical  or  elongated,  co- 
nical form,  traversed  by  one  or 
more  internal  longitudinal  ridges, 
and  closed  by  a  small  sub-circular 
valve  like  an  operculum  (p.  68). 

HIPPOPO'TOMI — Lat.  Plur.  of  hippo- 
potamus. 

HIPPOPO'TAMUS — fr.  gr.  'ippos,  horse, 
potamos,  a  river.  The  River-horse. 

HOLO'PTICUS,  and  HOLOPTT'CHIUS — 
fr.  gr.  0/05,  the  whole,  ptuchios, 
folded.  A  fossil  fish  of  the  ganoid 
order,  the  enamelled  surface  of 
whose  scales  was  marked  by  large 
undulating  furrows.  It  had  sharp 
conical  teeth  (p.  44). 

HO'MOCERCAL  —  fr.  gr.  omos,  joined, 
kerkos,  a  tail.  Applied  to  the  tail 
appended  to  the  termination  of  the 
spine,  as  in  most  of  the  fishes  now 
existing  (p.  49). 

HO'RJTBLEWDE  —  A  mineral  of  dark 
green  or  black  colour,  abounding 
in  oxide  of  iron,  and  entering  into 
the  composition  of  several  of  the 
trap  rocks.  There  are  three  varie- 
ties ;  common,  hornblende-schist, 
and  basaltic  hornblende. 

HORNBLENDE-SCHIST — A  slaty  varie- 
ty of  hornblende. 


HU'MTJS  —  Lat.  Moist  earth.  Vege- 
table earth  or  mould. 

HI/MERITS  —  Lat.  Shoulder.  Name 
of  the  bone  placed  between  the 
shoulder  and  elbow. 

HT'BODOKS  —  fr.gr.w6o5,  bent  out- 
wards, and  odous,  tooth.  A  divi- 
sion of  the  shark  family  (p.  44). 

HY'DRATED —  fr.  gr.  'udor,  water. 
Containing  water. 

HYDROCHLORIC  ACID — An  acid  com- 
posed of  hydrogen  and  chlorine, 
formerly  known  as  muriatic  acid. 

HYDHOSTA'TICS  —  fr.  gr.  'uddr,  wa- 
ter, stad,  I  stand.  The  scfence  which 
explains  the  properties  of  the  equi- 
librium and  pressure  of  liquids. 

HY'PERSTHENE  —  Labrador  horn- 
blende. It  contains  iron,  si'lica  and 
magnesia.  Hypersthene  rock  dif- 
fers from  common  hornblende  only 
in  its  foliated  crystallization  and  its 
pearly  or  metallic-pearly  lustre.  It 
is  a  very  tough  rock,  with  a  struc- 
ture resembling  gneiss. 

HYPNOIDES  —  fr.  gr.  upnon,  a  sort 
of  moss,  eidos,  resemblance.  Speci- 
fic name  of  a  fossil  plant. 

HY'POGESTE —  fr.  gr.  upo,  under,  gei- 
nomai,  I  am  formed.  A  class  of 
rocks  which  have  not  assumed  their 
present  form  and  structure  at  the 
surface  of  the  earth,  but  are  appar- 
ently of  igneous  origin  and  thrust 
up  from  below. 

HYPO'THESIS  —  fr.  gr.  upo,  under, 
tithemi,  I  place.  A  theory,  or  sup- 
position. A  rational  conjecture. 

HYPO'THETICAL  —  Of  the  nature  of 
hypothesis. 

I'CHTHYOSAU'RUS — The  fish  lizard  (p. 
57). 

IG'NEOUS  —  fr.  lat.  ignis,  fire.  Re- 
lating or  belonging  to  fire. 

IGUA'NODOX — From  iguana,  and  the 
Gr.  odous,  tooth.  An  extinct  genus 
of  gigantic  herbivorous  reptiles,  dis- 
covered in  the  south  of  England. 

IMBRICATA'RIA  —  Lat.  As  if  imbri- 
cated, or  tile-like. 

IMBRICA'TA  —  Lat.  Imbricate,  tile- 
like.  Arranged  like  tiles. 


S24 


GLOSSARY.  — GEOLOGY. 


IMPRE'SSA — Lat.  Impressed,  engrav- 
en, marked. 

INJEO.UIYA'LVIS  —  Lat.  Inequivalve. 
Having  unequal  valves. 

INCANDE'SCENCE —  fr.  lat.  incandes- 
cere,  to  grow  very  hot,  to  be  in- 
flamed. The  condition  of  great 
heat,  showing  a  certain  light,  as  if 
the  heated  substance  itself  were 
burning.  Melted. 

INCANDE'SCENT — Greatly  heated. 

INCOHE'RENT  —  fr.  lat.  in,  not,  con, 
with,  hsereoy  I  adhere.  Loose,  want- 
ing cohesion. 

INCLINATION  OF  BEDS  —  Dip  (p. 
185). 

INCRIJSTA'TION  —  fr.  lat.  eras/a,  a 
crust.  A  covering  like  a  crust. 

INEQJJILA'TERAL —  fr.  lat.  insequalis, 
unequal,  lotus,  (in  the  genitive, 
lateris,}  side.  Having  unequal 
sides. 

INFILTRATION  —  fr.  lat.  Jiltrare,  to 
filter.  The  act  of  filtering  through, 
producing  an  accumulation  of  li- 
quid. 

INOCE'RAMUS —  fr.  gr.  en,  with,  ke- 
ramos,  earthen  ware?  A  genus  of 
bivalve  fossil  shells,  which  are  chief- 
ly characterised  by  their  hinge  and 
the  fibrous  structure  of  their  con- 
stituent substance.  The  shell,  in 
consequence  of  the  vertical  arrange- 
ment of  the  fibres,  readily  breaks  to 
pieces,  and  it  is  often  extremely  dif- 
ficult to  extricate  a  specimen  with 
the  hinge  and  beaks  tolerably 
entire. 

IN  PLACE — In  their  original  position 
where  they  were  formed. 

INIUJINA'TA — Lat     Stained,  dirty. 

INSERTED — Attached. 

IN  SITU — Lat.    In  place. 

INTERCALATED  —  fr.  lat.  intercalo,  I 
place  between.  Placed  between. 

INTERCALATION  —  The  placing  one 
substance  between  others,  as  one 
stratum  between  two  others. 

INTERPOSED  —  fr.  lat.  inter,  between, 
pono,  I  place.  Placed  between. 

INTERTIUMPICAL —  Between  the  tro- 
pics. 


[NTRUSION  — The  act  of  thrusting  or 
forcing  in. 

I'SOLATED  —  fr.  it.  wo/a,  an  island. 
Separated  like  an  island. 

ISOTHE'RMAL —  fr.  gr.  isos,  equal, 
therme,  heat.  Isothermal  lines  are 
those  which  pass  through  those 
points  on  the  surface  of  the  earth, 
at  which  the  mean  annual  tempera- 
ture is  the  same. 

JA'SPER — A  siliceous  mineral  of  vari- 
ous colours. 

JOINTS  OF  DISLOCATION — (p.  187). 

JURA'SSIC  —  Belonging  to  the  Jura 
mountains. 

KEU'PER  —  Ger.  The  upper  portion 
of  the  new  red  sand-stone  forma- 
tion (p.  52). 

KJMMKIU I»<;K  CLAY — (p.  64). 

KlMMERIDGE    COAL (p.  65). 

KU'PFERSCHI'EFER  —  Ger.  Copper- 
slate  (p.  47). 

LA'BRADORITE  —  Labrador  spar.  It 
consists  of  silicate  of  alu'mina,  lime, 
and  soda,  with  traces  of  oxide  of 
iron.  It  is  a  variety  of  feldspar. 

LABTRI'NTIIICA  —  Lat.  Labyrinth- 
like. 

LABTRI'NTHODON  —  fr.  gr.  laburin- 
thos,  a  labyrinth,  odous,  tooth. 
An  extinct  genus  of  batrachians, 
characterised  by  teeth  of  a  peculiar- 
ly complicated  structure.  The  re- 
mains of  this  genus  peculiarly  cha- 
racterise the  Keuper  formation  in 
Germany  and  the  corresponding 
sand-stones  in  England  (p.  196, 
and  Jig.  307). 

LACE'RTIAN  —  fr.  lat,  lacerta,  a 
lizard.  Any  animal  of  the  lizard 
tribe. 

LACU'STRINE  —  fr.  lat.  locus,  a  lake. 
Belonging  or  relating  to  lakes. 

L.KVIS — Lat.     Smooth,  bare,  bald. 

LAM ANO'NIS — Specific  name  of  a  fos- 
sil plant. 

LAMBE'RTI —  The  name  of  Lambert 
latinized. 

LA'MINA — Lat.  Plur.  laminae.  A 
plate. 

LANDSLIP  or  LANESLIDE.  — The  re- 
moval of  a  portion  of  land  down 


GLOSSARY.  — GEOLOGY. 


an  inclined  surface,  from  its  at- 
tachment being  lessened  by  the  ac- 
tion of  water  beneath,  or  by  an 
earthquake. 

LAPI'LLI —  fr.  lat.  lapillus,  a  little 
stone.  Small  volcanic  cinders. 

LATERA'LIS — Lat.    Lateral. 

LA'VA  —  The  substances  which  flow 
in  a  melted  state  from  a  volcano. 
Lavas  vary  in  consistence  and  tex- 
ture. 

LE'NTA — Lat.    Slow,  heavy,  stupid. 

LEPIDODE'NDBA — Plur.  of  lepidoden- 
dron. 

LEPTDODE'NDBON — fr.  gr.  lepis,  scale, 
dendrun,  a  tree.  A  genus  of  fossil 
plants,  having  a  scaly  bark. 

LEPTE'NA — A  synonym  of  the  genus 
productus  (p.  30). 

LEYMERII — The  name  Leymerie  la- 
tinized. 

LIAS— (p.  54). 

LI'GNEOUS — fr.  lat.  lignum,  wood. 
Woody  ;  of  the  nature  of  wood. 

LI'GNITE — fr.  lat.  lignum,  wood.  A 
kind  of  coal. 

LI/MA  —  Lat.  A  file.  Name  of  a 
genus  of  bivalves. 

LINEA'RIS — Lat.    Linear,  line-like. 

LINE  OF  BEARING — Strike  (p.  185). 

LIQUEFA'CTION — The  act  of  becoming 
liquid. 

LITHU'ITES  and  LITU'ITES — fr.  lat. 
lituus,  a  crooked  staff.  Fossil 
chambered  shells,  curved  or  bent  at 
one  end  (Jig-  8). 

LITHOGHA'PHIC — fr.  gr.  lithos,  stone, 
grapho,  I  write.  Lithographic  stone, 
used  for  the  purposes  of  lithography 
(p.  65). 

LITIIO'PHAGI — fr.  gr.  lithos,  stone, 
phago,  I  eat.  Small  worms  found 
in  slate  which  give  it  a  red  co- 
lour. 

LITTORA'LIS  —  Lat.  Littoral ;  be- 
longing or  relating  to  the  shore. 

LOAM — A  mixture  of  sand  and  clay. 

LOHES — Veins  containing  metallic 
ores. 

LOESS  —  A  German  geological  term, 
applied  to  a  tertiary  alluvial  de- 
posit, which  occurs  in  patches  be- 


tween Cologne  and  Basle.  The 
term  is  applied  by  the  English  to 
that  peculiar  yellow  loam  with  cal- 
careous concretions. 

LONDON  CLAY — (p.  78). 

LONGIRO'STRIS — lat.  fr.  longus,  long, 
rostrum,  beak.  Long-billed. 

LONGISCA'TA  —  Lat.    A  little  longer. 

LT'COPO'DIA'CEJE  —  fr.  gr.  lukos,  a 
wolf,  pous,  foot.  A  natural  order 
of  plants  which  includes  the  ly'co- 
po'dium. 

LYELLH —  The  name  of  Lyell  la- 
tinized. 

LYMNE'A  or  IIMNEA — fr.  gr.  lirnne, 
a  pool.  A  genus  of  fresh-water 
snails. 

LU'CEM — Lat.     Light. 

LUGDITNENSIS  —  Lat.  Belonging  or 
relating  to  Lyons. 

LUMACHELLA — See  note  p.  67. 

MA'DREPO'RA —  Lat.  Compound  of 
the  French  madre,  spotted,  and 
Lat.  porus,  pore.  A  genus  of 
corals  (p.  141). 

MADREPORE — A  kind  of  coral. 

MADHEPO'RIC — Of  the  nature  of  ma- 
drepore. 

MAGNE'SIA — A  white,  tasteless  earthy 
substance. 

MAGNE'SIAN —  Relating  to,  or  con- 
taining magnesia. 

MAGNE'SIATC  LIMESTONE  —  Lime- 
stone which  contains  magnesia. 
An  extensive  series  of  beds  lying 
above  the  coal  measures. 

MAGNE'TIC — Having  properties  of  the 
magnet  or  load-stone. 

MAG'NUM — Lat.    Great. 

MAM'MAI. — Any  animal  that  suckles 
its  young. 

MAMMALI'FEROTJS— Containing  mam- 
mals. 

MAMMI'LLARY —  fr.  lat.  mammilla, 
a  little  nipple.  Studded  over  with 
small  rounded  projections. 

MAMMOTH  —  An  extinct  species  of 
elephant. 

MANTE'LLIA  —  A  genus  of  fossil  cy- 
ca'deffi,  named  in  honour  of  Mr. 
Mantell. 

MA'RGABETI'JERA  —  fr.  lat.  marga- 


226 


GLOSSARY. —  GEOLOGY. 


ritum,  a  pearl,  fero,  I  bear.    Pearl- 
bearing. 

MARINE — fr.  lat.  mare,  the  sea.  Re- 
lating to  the  sea. 

MAUL  —  Argillaceous  carbonate  of 
lime.  There  are  several  varieties 
of  marl. 

MA'RSHII  —  The  name  of  Marsh  la- 
tinized. 

MAHSU'PIAL  —  fr.  lat.  marsupium,  a 
pouch.  Any  animal  having  a  pe- 
culiar pouch  in  front  or  on  the  ab- 
domen. 

MA'STODON — fr.  gr.  mastos,  a  nipple, 
odous,  tooth.  A  genus  of  extinct 
quadrupeds  allied  to  the  elephant. 

WA'TRTX — Lat.  The  stony  substance 
in  which  metallic  ores  and  crystal- 
line minerals  are  imbedded.  Gan- 
gue. 

MAXIMUM — Lat.     Greatest. 

MEANDRI'NA — A  genus  of  polyps. 

MEANDIUV'^E —  Plur.  of  meandrina. 

MEDICAGJ/XELA — Specific  name  of  a 
chara,  a  kind  of  fossil  moss. 

MEDU'LLARY  HATS — fr.  lat.  medulla, 
marrow.  The  vertical  plates  of  cel- 
lular tissue  which  radiate  from  the 
centre  of  the  stem  through  the  wood 
to  the  bark  in  exogynous  plants. 

MEGALI'CHTH  YS — fr.  gr.  megas,  great, 
ichthus,  fish.  An  extinct  genus  of 
fishes,  including  species  of  great 
size. 

MEGA'LODON  —  fr.  gr.  megas,  great. 
odous,  tooth.  A  genus  of  peculiar 
fossil  bivalve  shells. 

MEGALO'NYX —  fr.  gr.  megas,  great, 
onux,  a  claw.  A  large  fossil  mam- 
mal, found  in  Virginia. 

MEGALOSAU'RUS — (p.  58). 

MEGATHE'KIUM — (p.  92). 

MELA'NIA — fr.  gr.  melas,  black.  A 
genus  of  fluviatile  univalves. 

MELA'PHYRY,  and  MELA'PHYRE — fr. 
gr.  melas,  black.  A  kind  of  por- 
phyry the  constituents  of  which  are 
united  by  a  black  cement  (p.  173). 

MEPHIT'IC — fr.  mephitis,  the  goddess 
of  foul  smells.  Applied  to  impure 
or  foul  exhalations. 

L]  'FZUOVS — Containing  metal. 


METAMO'RPHIC  —  Relating  to  meta- 
morphism. 

METAMO'RPHISM — fr.  gr.  rueta,  indi- 
cating change,  morphe,  form  (p. 
177). 

METAMO'RPHOSES — Plur.  of  metamor- 
phosis. 

METAMORPHOSIS — Change  of  form. 

MI'CA  —  fr.  lat.  mico,  I  shine.  A 
mineral  generally  found  in  thin 
elastic  laminae,  soft,  smooth  and  of 
various  colours  and  degrees  of 
transparency.  It  is  one  of  the  con- 
stituents of  granite. 

MICA'CEOUS — Of  the  nature  of  mica. 

MICA-SCHIST — Mica-slate  (p.  25). 

MI'CROSCOPE — fr.  gr.  mikros,  little, 
skoped,  I  view.  An  optical  instru- 
ment which  enables  us  to  examine 
objects  too  small  to  be  seen  by  the 
unassisted  eye. 

MI'CROSCOPIC — Minu'te ;  perceivable 
only  by  aid  of  a  microscope. 

MI'LLIOLITES,  or  MILI'OLA — fr.  lat. 
milium,  a  millet  seed,  and  gr.  lithos, 
stone.  A  genus  of  foramini'ferous 
fossil  shells  found  in  the  neighbor- 
hood of  Paris. 

MILLSTONE  GRIT  —  Coarse  grained, 
quartzose  sandstone. 

MINE — Ger.  Any  subterraneous  work 
or  excavation  which  has  for  its  ob- 
ject the  extraction  of  any  mineral 
products,  as  metallic  ores,  coal,  &c. 

MINERAL  —  Any  inorganic  natural 
object,  whether  solid,  liquid  or  gas- 
eous. 

MINERALOGY  —  That  branch  of  na- 
tural science  which  treats  of  the 
properties  of  minerals. 

MINIMA       }  r     i         T 

MI'NIMUM  $  Lat'     Least' 

MINUS — Lat.     Little. 

MINU'TA — Lat.     Minute,  very  small. 

MI'OCENE — (p.  78  and  83). 

MODERN  FORMATION — (p.  95). 
!  MOLA'SSE — Fr.   A  fine  grained  sand- 
stone, usually  soft  and  loose,  but 
sometimes     sufficiently     hard    for 
building  purposes. 

MOLLUSK — fr.  lat.  mollis,  soft.  Any 
animal  of  the  class  of  mollusca. 


GLOSSARY GEOLOGY. 


227 


MONI'LE — Lat.  Belonging  or  relat- 
ing to  a  necklace. 

MONILEFO'RMIS  —  lat.  fr.  monile,  a 
necklace,  forma,  form.  In  form  of 
a  necklace. 

MO'XOCOTY'LEDONS  —  fr.  gr.  tnonos, 
single,    kotuledon,    seed-lobe.     A 
class  of  plants  having  but  one  seed- 
lobe  in  the  embryo. 
MORAI'NES  —  Longitudinal    deposits 
of  stony  detritus  found  at  the  bases, 
and  along  the  edges  of  all  the  great 
glaciers  (p.  131). 
MOSASAU'RUS — (p.  75). 
MUCRONA'TUS — Lat.  Pointed,  sharp- 
pointed. 

MCLTILO'CULAR  —  fr.    lat.    multus, 
many,  loculus,  a  partition.     Hav- 
ing many  chambers  or  partitions. 
MTJ'RAL — fr.  lat.  murus,  a  wall.    Be- 
longing or  relating  to  a  wall. 
MTJ'REX — Lat.  A  shell  fish.  A  genus 

of  univalve  mollusks. 
MURICA'TA —  Lat.      Full   of    sharp 

prickles  or  points. 
MU'SCHELKALK — Ger.    (p.  50). 
MTTSCLE  —  An  organ  of  motion  ;  the 

flesh  of  animals. 
MTJ'SSEI, — A  bivalve  mollusk. 
MUTA'BILE' — Lat.    Mutable,  change- 
able. 

MT'A — A  genus  of  bivalve  mollusks. 
NA'GELFLTJE — Ger.     A  coarse  con- 
glomerate. . 

NATJ'TILUS — A  genus  of  cephalopods. 

NAVI'CTJLA — Lat.    A  little  boat. 

NEOCO'MIAN    and    NEOCOMIEN —  Fr. 

The  lower  beds  of  the  cretaceous 

system  in  the  south  of  France  and 

elsewhere,    are    described    by    the 

French  geologists  under  this  name. 

NEPTUNIAN — From   Neptune,  god 

of  the  sea.     Belonging  or  relating 

to  water, 

NERI'NEA —  A  genus  of  fossil  uni- 
valves, resembling  both  Cere'thium 
and  Turritella  (p.  63). 
NERVCRES — Veins  of  leaves.     Also, 
the  tubes  for  expanding  the  wings 
of  insects. 
NEURO'PTERA — fr.gr.  neuron,  a  nerve 
pteron,  wing.    An  order  of  insects 


NEURO'PTERIS  —  A  genus  of  fossil 
plants  (p.  41). 

NEW    RED    SAND-STONE (p.  47). 

NIDIFO'HMIS  —  Lat.  In  form  of  a 
bird's  nest. 

NILSO'NIA — A  genus  of  fossil  plants. 

NODO'SUS — Lat.     Knotty. 

NO'DTTI.E — fr.  lat.  nodus,  a  knot.  A 
rounded  irregular  lump  or  mass. 

NOR'MAL — fr.  lat.  norma,  a  rule.  Ac- 
cording to  the  peculiarities  of  a 
family  or  genus,  without  the  least 
departure. 

NORWICH,  or  NORFOLK  CRAG  —  A 
tertiary  formation  which  rests  on 
the  London  clay  or  chalk,  and  in- 
cludes marine  shells  (p.  84). 

NU'CLEUS  —  Lat.  A  kernel.  The 
solid  core  of  a  body. 

NU'CULA  —  fr.  lat.  nux,  a  nut.  A 
genus  of  bivalve  shells  with  nume- 
rous teeth  like  those  of  a  comb. 

NUMMULI'TES  —  fr.  lat.  nummus, 
money,  and  fr.  gr.  lithos,  stone. 
Fossil  money.  An  extinct  genus 
of  cephalopods,  of  a  thin  lenticular 
shape,  divided  internally  into  small 
chambers.  Nummulite  limestone 
obtains  its  name  from  the  presence 
in  it  of  these  shells  in  great  abund- 
ance. In  Alabama  there  is  a  moun- 
tain range  entirely  composed  of 
one  species  of  nummulite. 

NOTRI'TION — The  animal  function  by 
which   the  various  organs  receive 
nutritive  substances  (previously  pre- 
pared by  the  several  organs  of  di- 
gestion), necessary  to  repair  their 
losses  and  maintain  their  strength. 
OBLO'NGUS — Lat.     Oblong. 
OBOVA'TA — Lat.     Obovate. 
OBO'YATE  —  fr.  lat.  ob,  for,  opposite, 
ovum,  egg.     Reverse  of  ovate  or 
egg-shaped. 

OBSI'DIAN  —  Named  after  Obsidius. 
A  glassy  lava.  Volcanic  glass.  It 
consists  of  si'lica  and  alu'mina  with 
a  little  potash  and  oxide  of  iron. 
OCTOPLICA'TA — Lat.  octo,  eight,  pli- 
ca'ta,  folded.  Having  eight  folds. 

OLD    RED    SANDSTONE (p.  37). 

O'OLITE — fr.  gr.  00/2,  an  egg,  lithos, 


228 


GLOSSARY.—  G  EC 


stone.  A  granular  variety  of  car- 
bonate of  lime,  frequently  called 
roeslone  (p.  58). 

O'oLixic  —  Belonging  or  relating  lo 
o'olite. 

OpALE'scEirr —  Resembling  o'pal,  a 
beautiful  mineral,  characterized  by 
its  iridescent  reflection  of  light. 

OPE'RCULUM — fr.  lat.  operio,  I  cover. 
The  lid  which  protects  the  gills  of 
fishes,  and  closes  the  opening  of 
certain  univalve  shells. 

ORBICULA'RIS — Lat.     Orbicular. 

ORBIT — fr.  lat.  orbis,  a  circle.  The 
circular  cavities  in  which  the  or- 
gans of  vision  are  lodged,  are  named 
the  orbits. 

ORES — fr.  ger.  erzc.  Mineral  bodies 
from  which  metals  are  extracted. 

ORGAIT  —  fr.  gr.  organon,  an  instru- 
ment. Part  of  an  organized  being, 
destined  to  perform  some  particular 
function  ;  the  ears  are  organs  of 
hearing,  the  muscles  organs  of  mo- 
tion, &c. 

ORGA'XIC — Relating  to  organs. 

ORGANIZED — Possessing  organs. 

ORGAifizA'Tioir —  A  mode  of  struc- 
ture. 

OHGA'JTISANS  —  Lat.  fr.gr.  organoo, 
I  arrange,  or  provide  with  organs. 
Organizing,  constructing. 

ORTHTS  —  A  genus  of  fossil  bivalve 
shells  (p.  29). 

OHTHOCE'RAS —  ">  .      _ 

ORTHO'CERATITE  j  O  dS> 

OSCILLA'TIOX  —  fr.  lat.  oscillum,  an 
image,  hung  on  ropes  and  swung 
up  and  down  in  the  air.  The  act 
of  moving  backwards  and  forwards 
like  a  pendulum. 

OSCILLA'TORY — Swinging  backwards 
and  forwards  like  a  pendulum. 

OSTRA'CEA — Family  of  bivalves  which 
includes  the  oyster. 

OS'TREA  —  Genus  of  bivalves ;  an 
oyster. 

OUTCROP — The  emergence  of  a  rock, 
in  place,  at  the  surface. 

OUTLIER  —  A  hill  or  range  of  strata 
occurring  at  some  distance  from  the 


general  mass  01  formation  to  which 
it  belongs. 

OVA'TUS — Lat.     Ovate,  egg-shaped. 

OVERLYING — When  one  stratum  lies 
over,  or  overlaps  another,  it  is  said 
to  be  overlying. 

OXFORD  CLAY — (p.  62). 

O'XIDE  —  fr.  gr.  oxus,  acid,  eidos, 
form.  A  compound,  which  is  not 
acid,  containing  oxygen. 

O'xYGEtf — fr.  gr.  oxus,  acid,  gennein, 
to  generate.  Vital  air. 

PA'CHYDE'RMA  —  Lat.  fr.  gr.  pachus, 
think,  derma,  skin.  Thick-skin- 
ned. 

PA'CHYDE'RMATA  —  Lat.  Pa'chy- 
de'rms. 

PACHYUE'RMS — An  order  of  quadru- 
peds, including  the  elephant,  horse, 
pig,  &c.,  distinguished  by  the  thick- 
ness of  their  hides. 

PA'CHYDE'RMATOUS — Relating  to  pa'- 
chyde'rms. 

PA'CHYGJTA'TUS — Lat.  fr.  gr.  pachus, 
thick,  gnathos,  jaw.  Specific  name 
of  the  labyrinthodon  (p.  197). 

PAL^OXI'SCUS — (p.  48). 

PA'LJEOXTO'LOGIST —  One  skilled  in 
paleontology. 

PALJEOXTO'LOGY — fr.  gr.  palaios,  an- 
cient, on,  creature,  logos,  a  dis- 
course. That  branch  of  zo'ological 
science  which  treats  of  fossil  organic 
remains. 

PALJE'OZOIC — fr.  gr,  palaios,  ancient, 
zoe,  life.  Relating  to  ancient  life. 

PALEOTHE'RIUM — (p.  83). 

PALMACI'TES  —  A  genus  of  fossil 
plants. 

PALUDI'NA — fr.  lat.  palus,  a  marsh. 
A  genus  of  fresh  water  gasteropods. 

PALUDI'ITE — Plur.  of  paludina. 

PALUDINE — Belonging  to  a  marsh. 

PARALLEL  —  Extended  in  the  same 
direction  and  preserving  always  the 
same  distance. 

PARALLE'LISM — The  state  of  being 
parallel. 

PARALLE'PIPED  —  A  solid  contained 
by  six  planes,  three  of  which  are 
parallel  to  the  other  three. 


GLOSSARY.  — GEOLOGY. 


229 


PA'RASITE  —  An  adherent,  a  hanger  on. 
PARASI'TIC  —  Of  the  nature  of  a  para- 

site. 
PARI'ETES  —  fr.  lat.  paries,  a  wall. 

The  sides  or  parts  forming  an  en- 

closure. 
PARIS  BASIN  —  (p.  79). 


PECO'PTERIS  —  fr.  gr.  pekos,  sheep- 

skin, pteris,  a  fern.  A  genus  of  fos- 

sil ferns. 
PE'CTEK  —  Lat.     A  comb.     A  genus 

of  bivalve  mollusks. 
PECTIKA'TA  —  Lat.     Pectinate;  like 

the  teeth  of  a  comb. 
PE'LLICLE  —  fr.  lat.  pellis,  a  skin.     A 

thin  skin,  or  crust. 
PEJTINE  FORMATION  —  New  red  sand- 

stone (p.  47). 
PENTA'MERUS  or  PENTAME'RUS  —  fr. 

gr.  pente,  five,  meros,  a  part  (p.  31). 
PEJTTA'NGULA'TUS  —  Lat.      Having 

five  angles. 
PERCOLATE  —  fr.  lat.  per,  through, 

co/o,  I  strain.     To  strain  or  drip 

through. 
PE'RIDOT  —  Prismatic  chrysolite  (p. 

121). 
PE'RLITE  —  Pearlstone,  a  gray  variety 

of  obsidian. 
PERMANENT  GAS  —  Any   gas  which 

remains  in  the  aeriform  state  under 

ordinary  circumstances. 
PERO'XIDE  —  The  highest  degree  of 

oxidizement  of  which   a  metal  or 

other  substance  is  susceptible  with- 

out becoming  an  acid. 
PES-PELICA'NI  —  Lat.     Pelican   foot. 
PHANEROGA'MIA  —  fr.  gr.  phaneros, 

evident,  gamos,  marriage.    The  di- 

vision of  the  vegetable  kingdom  in 

which  all  the  plants  bear  flowers, 

and  are  multiplied  by  means  of  true 


PHANERO'GAMOUS — Belonging  or  re- 
lating to  phaneroga'mia. 

PHEjfo'MEjr A — Plur.  of  phenomenon. 

PHENO'MENON — Gr.  Appearance,  vi- 
sible quality,  event. 

PHO'LAS  —  fr.  gr.  p/ioleos,  a  lurking 
place.     A  genus  of  mollusks. 
20 


PHO'LADKS — Plur.  of  Pholas. 

PHO'LODOMY'A —  A  genus  of  mol- 
lusks. 

PHO'NOLITE  —  Clinkstone,  a  species 
of  compact  basalt,  which  is  sonor- 
ous when  struck  (p.  171). 

PHOSPHO'HIC  ?  fr.  gr.  phos,  light. 

PHOSPHORE'SCEST  3  Emitting  light 
in  the  dark. 

PISTILLIFO'RMIS — Lat.  In  form  of  a 
pistil. 

PLACOIDEANS — (p.  48). 

PLACU'NEA  —  Lat.  fr.  gr.  plakoeis, 
broad,  flat,  even. 

PL.EXERKALK — Ger.     (p.  71). 

PLAGIO'STOMA —  fr.  gr.  plagios,  ob- 
lique, stoma,  mouth.  A  genus  of 
bivalve  mollusks. 

PLANO'RBIS — fr.  lat.  planus,  flat,  or- 
bis,  a  circle.  A  genus  of  marsh 
snails  (p.  83). 

PLA'NUS— Lat.     Flat. 

PLASTIC  CLAY — (p.  78). 

PLASTER  OF  PARIS — A  substance  pre- 
pared by  heating  gypsum. 

PLA'TEAU — Fr.  An  elevated  plane, 
or  table  land. 

PLA'TEAUX  (PLA'-TO) — Plur.  of  pla- 
teau. 

PLATI'N A  or  PLATI'NITM — fr.  sp.  pla- 
ta,  silver,  on  account  of  its  colour. 
A  metal  of  a  whitish  colour,  exceed- 
ingly ductile,  malleable,  and  of  diffi- 
cult fusion. 

PLATTSO'MUS — (p.  48). 

PLEI'SIOSAU'RUS — (p.  57). 

PLEIS'TOCENE  —  fr.  gr.  pleistos,  the 
most,  kainos,  recent.  The  newer 
pliocene  formation  or  newest  tertia- 
ry- 

PLEU'RONECTES — fr.  gr.  pleura,  side, 
nektes,  swimmer.  A  genus  of 
fishes. 

PLEURO'TOMA  —  fr.  gr.  pleura,  side, 
tome,  a  notch.  A  genus  of  univalve 
mollusks,  having  a  notch  in  the 
side  of  the  shell. 

PLEUROTOMA'RIA  —  A  tribe  of  mol- 
lusks. 

PLICA'TULA — fr.  lat.  plica,  a  fold.  A 
genus  of  mollusks  (p.  72). 

PLI'OCENE — (p.  78  and  89). 


230 


GLOSSARY.  — GEOLOGY. 


PLUTONIC  —  After  Pluto,  the  god  of 
fire.  Relating  to  fire. 

POIKILI'TIC  —  fr.  gr.  poikilos,  varie- 
gated. A  name  applied  to  the  new 
red  sandstone  formation  in  con- 
sequence of  the  varieties  of  colours 
it  exhibits. 

PO'LYP  —  fr.  gr.  polus,  many,  pous, 
foot.  A  radiated  animal  which  has 
a  cylindrical  or  oval  body,  or  sac, 
with  an  opening  at  one  extremity, 
around  which  are  long  feelers. 

POLYPA'HIA,  and  POLTPIA'RIA  — 
Groups  of  polyps  or  animalcules 
which  form  coral. 

POLYPA'RIUM—  The  skeleton  or  frame- 
work formed  by  coral  animalcules. 
When  this  frame-work  is  of  a  stony 
hardness  it  constitutes  coral.  In 
fossils  the  polyparium  alone  re- 
mains. 

PO'ROUS  —  Containing  pores. 

PORPHTRI'TIC  —  Of  the  nature  of  por- 


POR'PHYROID  —  Resembling  porphyry. 

PORPHYRY  —  fr.  gr.  porphura,  purple. 
Originally  applied  to  a  red  rock 
found  in  Egypt.  A  compact  feld- 
spalhic  rock  containing  disseminat- 
ed crystals  of  feldspar,  the  latter 
when  polished,  forming  small  angu- 
lar spots,  of  a  light  colour,  thickly 
sprinkled  over  the  surface.  The 
rock  is  of  various  colours,  dark 
green,  red,  blue,  black,  &c. 

PORRE'CTA  —  Lat.     Extended. 

PORTLAND  O'OLITE  —  (p.  64). 

POSIDO'NIA  —  (p.  52). 

POZZUOLA'NA  and  POUZZUOLANI  — 
Volcanic  ashes  used  in  the  manu- 
facture of  mortar  which  hardens 
under  water:  exported  from  Poz- 
zuoli,  near  Naples. 

PRECIPITA'TION  —  The  action,  by 
which  a  body  abandons  a  liquid  in 
which  it  is  dissolved  or  suspended, 
and  becomes  deposited  at  the  bot- 
tom. 

PRISMA'TICUM  —  Lat.     Prismatic. 

PRODU'CTUS  —  A  genus  of  extinct  mol- 
lusks  (p.  29,  30,  and  39). 


PTERI'CHTHYS — (p.  32). 

PTERODA'CTYLI — Lat.  Plur.  of  pte- 
rodactyl us. 

PTERODA'CTYLUS — (p.  57). 

PTERO'PH  YLLUM — fr.  gr.pteron,  wing, 
phullon,\eaf.  A  genus  of  fossil  plants. 

PUDDING  STONE — Conglomerate. 

P.UMICE — Vesicular  obsidian. 

PY'RITES —  A  compound  of  sulphur 
and  iron. 

PY'ROXENE— (p.  121). 

PYROXENIC —  Of  the  nature  of  py- 
roxene. 

QUADERSANDSTEIN — Ger.  The  lower 
cretaceous  beds  in  Germany :  any 
sandstone  fit  for  building  purposes. 

QUAQ.UAVERSAL — Turning  each  way. 

QUARRY  —  A  stone  mine ;  a  place 
where  stones  are  dug. 

QUARTZ — Ger.  Rock  crystal.  A  con- 
stituent of  granite  and  some  other 
rocks. 

QUA'HTZOSE — Of  the  nature  of  quartz. 

RADIA'TA — Lat  Radiate :  the  name 
of  a  class  of  zo'ophytes. 

RA'DTATE  —  fr.  lat.  radius,  a  ray. 
Furnished  with  rays. 

RA'DIUS  —  Lat.  A  ray.  The  semi- 
diameter  of  a  circle  ;  a  ray  drawn 
from  the  centre  to  the  circumference. 

RADIA'TTON —  The  emission  of  rays 
of  light,  or  of  heat,  from  a  luminous 
or  a  heated  body. 

RA'DIOLITES  —  A  genus  of  fossil 
shells  ;  the  inferior  valve  of  which 
is  in  the  shape  of  a  reversed  cone, 
the  superior  valve  convex  (p.  69). 

RAFT  —  Trunks  of  trees  and  other 
vegetable  debris  matted  together,  by 
natural  causes,  and  sunk  in  a  river 
or  stream. 

RAG— (p.  59). 

RAPI'LLI — Small  volcanic  cinders. 

REACTION — The  force  exerted  by  two 
bodies  which  act  mutually  on  each 
other. 

REA'LGAR — Red  sulphnret  of  arsenic. 
A  compound  of  sulphur  and  ar- 
senic. 

REFRIGERA'TION —  The  act  of  cool- 
ing. 


GLOSSARY.  — GEOLOGY. 


231 


RESINOUS — Containing  resin. 

RETU'SUS — Lat.     Retuse  ;  blunted. 

RKVOLU'TA — Lat.     Turned  again. 

ROCK — Any  mineral  aggregate  (p.13). 

RODENTIA —  fr.  lat.  rodere,  to  gnaw. 
An  order  of  mammals. 

RODENTS — Gnawers  ;  animals  of  the 
order  of  rodentia. 

ROLLED  FLINTS — (p.  129). 

ROSTELLA'RIA  —  fr.  lat.  rostellum,  a 
little  beak.  A  genus  of  univalve 
mollusks  (p.  85). 

ROTHOMAGE'NSIS —  Lat.  from  rotho- 
ma'gum,  a  temple  of  Roth,  a  di- 
vinity of  that  part  of  Gaul,  now 
called  Normandy ;  hence  too  the 
name  of  the  city  Rouen.  Belong- 
ing or  relating  to  Rouen.  Specific 
name  of  an  ammonite. 

ROTHE-TODTE-LIEGENDE Ger.    New 

red  sandstone  (note,  p.  47). 

ROTA'TA  —  Lat.  Rotate;  wheel- 
shaped. 

ROTU'NDUS — Lat.     Round. 

RUBBLE  —  Angular  and  broken  frag- 
ments of  subjacent  rock  lying  be- 
neath the  superficial  mould. 

RUDI'STES — fr.  lat.  rudis,  unacquaint- 
ed, because  the  characters  of  the 
animal  were  unknown.  Name  of 
a  family  of  extinct  mollusks  in  the 
shells  of  which  neither  the  hinge, 
the  ligament  of  the  valves,  nor  the 
muscle  of  attachment  is  discover- 
able. The  family  contains  six 
genera :  Spherulite.s,  Radiolites, 
Calceola,  Birostrites,  Distinct,  and 
Crania. 

RC'GOSA — Lat.     Rugose,  wrinkled. 

RUGOSITY — A  wrinkling. 

RUMINA'NTIA —  Order  of  mammals 
which  chew  the  cud. 

RUMINANTS — Animals  that  chew  the 
cud. 

RYA'COLITE — (p.  120). 

SACCHAROID  —  fr.  lat.  saccharum, 
sugar,  and  gr.  eidos,  resemblance. 
Resembling  loaf-sugar. 

SAL-AMMONIAC  —  A  compound  of 
ammonia  and  hydrochloric  acid. 
Muriate  of  ammonia. 


SALI'FEROUS  FORMATION  —  (p.  47). 

SALT  —  Any  combination  of  an  acid 
with  a  saliiiable  substance. 

SANDALI'NA — Lat.     Sandal-like. 

SANDSTEIN — Ger.     Sandstone. 

SANDSTONE — Any  rock  consisting  of 
aggregated  grains  of  sand. 

SAU'RIANS  —  fr.  gr.  sauros,  a  lizard. 
Animals  of  the  lizard  tribe. 

SAUROID — fr.  gr.  sauros,  a  lizard,  ez- 
dos,  resemblance.  Resembling  a 
lizard. 

SAXI'GENOUS —  fr.  lat.  saxum,  rock, 
and  gr.  geinomai,  I  produce.  Rock 
producing ;  rock  forming. 

SCA'BRA — Lat.     Rough. 

SCAPIII'TES — fr.  gr.  skapke,  a  boat. 
The  boat  ammonite  (p.  73). 

SCHIST  —  Ger.  fr.  gr.  schistos,  split. 
Slate. 

SCHISTO'SE — Slaty. 

SCO'RI^  —  Lat.  plur.  of  scoria,  dross. 
Volcanic  cinders.  Cinders  and 
slags  of  basaltic  lavas  of  a  reddish 
brown  and  black  colour. 

SCORIA'CEOUS  —  Of  the  nature  of 
scoria?. 

SCO'RIFORM — In  form  of  scoriae. 

SEAMS — Thin  layers  or  strata  inter- 
posed between  others. 

SECONDARY  FORMATION — (p.  36). 

SECRETED  —  Separated  by  the  action 
of  organs. 

SE'DIMENT  —  fr.  lat.  sedeo,  I  sit,  that 
which  subsides,  or  settles  to  the 
bottom  of  any  liquid  ;  dregs. 

SEDIME'NTART — Belonging  or  relat- 
ing to  sediment. 

SEL'ENITE — A  variety  of  gypsum. 

SELLA — Lat.     A  saddle. 

SEMICRT'STALLINE  —  Partly  crystal- 
line. 

SENSIBLY — Perceptibly. 

SE'PIA — A  kind  of  paint  or  ink  pre- 
pared from  the  cuttle-fish. 

SEPTA — Lat.  plur.  of  septum. 

SEPTA'RIA — »  Flattened  balls  of  stone, 
which  have  been  more  or  less 
cracked  in  different  directions  and 
cemented  together  by  mineral  mat- 
ter which  fills  the  fissures." 


232 


GLOSSARY.  — GEOLOGY. 


SEPTUM — Lat.     A  partition. 

SERIATE' — Lat.  fr.  seria,  ajar.  Jar- 
like. 

SER'PENTINE — A  magnesian  rock  of 
various  colours  and  often  speckled 
like  a  serpents  back.  It  is  gene- 
rally dark  green. 

SER'PULA — fr.  lat.  serpo,  I  creep.  A 
genus  of  anneli'dans  which  inhabit 
a  calcareous  tube,  usually  adherent 
to  the  shells  of  mollusks. 

SES'SILE —  fr.  lat.  sessilis,  dwarfish. 
Without  a  pedicle  or  support. 

SHALE — An  indurated  slaty  clay,  or 
clay-slate. 

SHIITGLE — Loose,  water-worn  gravel 
and  pebbles. 

SIGILLA'RIA  —  fr.  lat.  si'gillum,  a 
seal.  Fossil  plants  found  in  the 
coal  formation. 

SI'LEX — fr.  gr.  chalis,  a  pebble.  The 
principal  constituent  of  quartz,  rock- 
crystal,  flint,  and  other  silicious 
minerals. 

SI'LICA — Silicious  earth ;  the  oxide  of 
silicon  (the  elementary  basis  of  si- 
lica), constituting  almost  the  whole 
of  silex  or  flint.  It  combines  with 
many  of  the  metallic  oxides,  and 
is  hence  sometimes  called  sili'cic 
acid. 

SI'LICATE  —  A  compound  of  silicic 
acid  and  a  base  ;  silicate  of  iron  is 
a  compound  of  silicic  acid  and 
oxide  of  iron ;  plate-glass  and  win- 
dow-glass are  silicates  of  soda  and 
potassa,  and  flint-glass  is  a  similar 
compound  with  a  large  addition  of 
silicate  of  lead. 

SILI'CIOUS — Containing  silica. 

SILI'CIFIED — Petrified  or  mineralized 
by  silicious  earth. 

SILT  —  The  name  given  to  the  sand, 
clay,  and  earth  which  accumulate 
in  running  waters. 

SILU'RIAIT  STSTEM — Series  of  rocks 
formerly  known  as  the  greywacke 
series  (p.  28). 

SIITUA'TA — Lat.    Hollow,  excavated. 

Si'srus  —  Lat.  A  hollow  or  excava- 
tion. 


SINUO'SITT — A  hollow,  an  irregular, 
winding  excavation  or  hollow. 

SI'PHOW  —  fr.  gr.  siphon,  a  tube.  A 
cylindrical  canal,  perforating  the 
partitions  of  multilocular  shells. 

SI'PHUNCLE — A  small  siphon. 

SLATE  —  A  well  known  rock,  which 
is  divisible  into  thin  plates  or 
layers. 

SOCIA'LIS — Lat.  Social ;  relating  to 
companions. 

SOLFATA'RA  —  It.  A  volcanic  vent 
emitting  sulphur  and  sulphurous 
compounds  (p.  115). 

SOLEM — Lat.     The  sun. 

SOMMA— It.     (p.  103). 

SPATA'NGUS — fr.  gr.  spataggos,  a  spe- 
cies of  echinus.  A  genus  of  sea- 
urchins,  having  the  mouth  situated 
laterally,  and  but  four  rows  of 
pores. 

SPECIES  —  A  kind  ;  a  subdivision  of 
genus. 

SPECIFIC  "WEIGHT,  or  SPECIFIC  GRA- 
VITY— The  relative  weight  of  one 
body  with  that  of  another  of  equal 
volume. 

Sp;Eifo'pTERis  —  fr.  gr.  sphen,  a 
wedge,  pteris,  a  fern.  A  genus  of 
fossil  plants. 

SPHE'NOPHT'LLITES  —  fr.  gr.  sphen, 
wedge,  phullon,  leaf,  lithos,  stone. 
A  family  of  fossil  plants. 

SPHE'RULITES  —  fr.  gr.  sphaira,  a 
sphere,  lithos,  a  stone.  A  variety 
of  obsidian  or  pearlstone  which 
occurs  in  rounded  grains. 

SPINO'SA     7ljat'     Spinous;  covered 

SPIXO'SUM  5      with  spines. 

SPI'RIFER — (p.  30). 

STALA'CTITES — fr.  gr.  stalasso,  I  drop. 
Conical  concretions  of  carbonate  of 
lime  attached  to  the  roofs  of  calca- 
rious  caverns,  and  formed  by  the 
gradual  dropping  of  water  holding 
the  carbonate  in  solution. 

STALA'GMITES  —  Stalactical  forma- 
tions of  carbonate  of  lime,  found 
on  the  floors  of  calcareous  caverns. 

STAU'HOTIDE — fr.  gr.  stauros,  a  cross, 
eidos,  form.  Cross-stone.  Pris- 


GLOSSARY.  — GEOLOGY. 


233 


matic  garnet.  It  is  very  abundant 
in  New  England. 

STELLAS — Lat.     Stars. 

STIGMA'RIA  —  fr.  gr.  stigma,  an  im- 
pression. A  vegetable  fossil  (p.  42). 

STHA'TA — Lat.  plur.  of  stratum. 

STRA'TUM — Lat.     A  layer,  a  bed. 

STRATTFICA'TION — An  arrangement 
in  beds  or  layers. 

STRA'TIFIED — Arranged  in  strata. 

STRIPS  —  Lat.  Diminutive  channels 
or  creases. 

STRIATED — Marked  with  strise. 

STRIKE — The  direction  of  strata  ;  the 
line  of  bearing  (p.  185). 

SUB — Lat.     Under. 

SUBAPENNINE — Applied  to  a  portion 
of  the  pliocene  strata.  Low  hills 
which  border  the  Apennines. 

SUBLIMA'TION  —  The  process  by 
which  volatile  substances  are  raised 
by  heat,  and  again  condensed  into 
the  solid  form.  The  substances  so 
obtained  are  called  sub'limates. 

SUBMARINE — Beneath  the  sea. 

SUBMERGED  —  Immersed  or  covered 
by  water. 

SUBPLICA'TA — Lat.  Somewhat  plait- 
ed. 

SUBSIDENCE — (p.  99). 

SUBSTRATUM  —  An  under-layer  or 
bed. 

SULCA'TA    }  Lat.     Sulcate  ;  grooved 

SULCA'TUS  3      or  furrowed. 

SULPHATISA'TION —  The  act  of  con- 
verting into  compounds  containing 
sulphur. 

SUL'PHURET —  A  compound  of  sul- 
phur with  an  other  solid. 

SULPHU'RIC   ?  Relating    to   sulphur. 

SULPHUROUS  3  Applied  to  acids 
composed  of  sulphur  and  oxygen. 

SUPERPOSED — fr.  lat.  super,  above, 
pono,  I  place.  Placed  above. 

SYENITE  and  SIENITE —  A  granitic 
rock  from  Syene  or  Siena,  in  Egypt. 
It  consists  of  quartz,  feldspar  and 
hornblende.  It  is  tougher  than 
granite  and  a  more  durable  building 
stone. 

SYNCLINAL — fr.  gr.  sun,  with,  klinein, 
to  incline.  Synclinal  axis  (p.  160). 
20* 


STSTEM  OF  UPHEAVAL — (p.  189  and 
191). 

TABULAR — In  form  of  a  table;  hori- 
zontal. 

TALC — A  foliated  magnesian  mineral 
of  an  unctuous  feel,  often  used  for 
tracing  lines  on  wood,  cloth,  &c. 
which  are  not  so  easily  effaced  as 
those  of  chalk. 

TAL'COSE — Of  the  nature  of  talc. 

TA'LUS— A  sloping  heap  of  fragments 
accumulated  at  the  foot  of  a  steep 
rock. 

TEMPERATURE — A  definite  degree  of 
sensible  heat. 

TENDON — f.  gr.  teino,  I  stretch.  A 
fibrous  cord  at  the  extremity  of  a 
muscle,  by  which  the  muscle  is 
attached  to  a  bone. 

TEREBE'LLUM — fr.  lat.  terebro,  I  bore. 
A  genus  of  gasteropod  mollusks. 

TEREBRA'TULA — (p.  30). 

TER'MINAL — Belonging  to  the  end. 

TERTIARY  FORMATION — (p.  77). 

TESTA'CEOUS — fr.  lat.  testa,  a  shell. 
Consisting  of  carbonate  of  lime  and 
animal  matter. 

TESTUDINA'RIA — A  tribe  of  chelonian 
reptiles. 

THE'RMAL  —  fr.  gr.  therme,  heat. 
Warm,  hot. 

THE'RMOMETER — fr.  gr.  therme,  heat, 
metron,  measure.  An  instrument 
for  measuring  heat.  .„ 

THIN  OUT  —  Strata  are  said  to  thin 
out  when  they  diminish  in  thickness. 

TISSUE — fr.  lat.  tela,  a  web.  A  web, 
or  web-like  structure,  constituting 
the  elementary  structures  of  ani- 
mals and  plants. 

TRA'CHYTE  —  fr.  gr.  trachus,  rough. 
A  variety  of  lava.  A  feldspathic 
rock,  which  often  contains  glassy 
feldspar  and  hornblende.  When 
the  feldspar  crystals  are  thickly  and 
uniformly  disseminated,  it  is  called 
trachytic  porphyry. 

TRANSITION  FORMATION  —  (p.  26). 

TRAP  —  From  the  Sweedish  trappa, 
a  flight  of  stairs,  because  trap  rocks 
frequently  occur  in  large  tabular 
masses  rising  one  above  another 


234 


GLOSSARY.  — GEOLOGY. 


like  the  successive  steps  of  a  stair 
case.  Applied  to  certain  igneous 
rocks  composed  of  feldspar,  augite 
and  hornblende. 

TRA'PPEAN — Relating  to  trap  rocks. 

TRAPEZOIDAL  —  In  form  of  a  trape- 
zium. 

TRA'VERTIN — fr.  it.  travertino.  Lime- 
stone deposited  from  water  holding 
carbonate  of  lime  in  solution.  It  is 
found  in  the  sweet  springs  of  Vir- 
ginia, and  at  the  hot  springs  of  the 
Washita,  in  Arkansas,  as  well  as  in 
many  other  places. 

TRE'MOLITE  —  A  mineral,  often  of  a 
fibrous  structure,  generally  contain- 
ing si'lica,  magnesia,  and  carbonate 
of  lime,  originally  found  in  the 
valley  of  Tremola  on  St.  Gothard. 

TRENCHANT — Cutting. 

TRIAS — fr.  lat.  tres,  three  (p.  49). 

TRIA'SSIC — Of  the  nature  of  trias. 

TRIGONA'LIS — Lat.  fr.  gr.  treis,  three, 
gonia,  angle.  Having  three  angles 
or  corners. 

TRIGO'NIA —  fr.  gr.  trigonos,  three- 
cornered.  A  genus  of  bivalve  mol- 
lusks  most  of  which  are  extinct. 

THIGO'NULA  —  Lat.  Having  three 
little  angles. 

TRILOBITE — (p.  28). 

TRITURA'TION — fr.  \&t.tritus,  rubbed. 
The  act  of  rubbing  or  grinding. 

TRUNCATE  —  Terminating  very  ab- 
ruptly, as  if  a  portion  had  been  cut 
off. 

TRUNCA'TUS — Lat.     Truncate. 

TU'FA —  It.  A  volcanic  rock,  com- 
posed of  an  agglutination  of  frag 
mented  scorise. 

TURBO — Lat.  A  twisting.  A  genus 
of  univalve  gasteropods. 

TURBINA'TA     7  Lat.     Shaped  like  a 

TURBINA'TUM  5      top. 

TURRI'CULATED— Resembling  a  tower 
with  turrets. 

TURRILITES — (p.  73). 

TURRITE'LLA  —  Lat.  A  little  tower 
or  turret.  A  genus  of  gasteropods 

UNCONFORMABLE  STRATIFICATION — 
(p.  185). 


JNDULA'TION — A  wave ;  arranged  in 
a  wave-like  manner. 

[JNDULA'TUS — Lat.  Waved;  hav- 
ing a  waved  surface. 

UNILO'CULAR — fr.  lat.  unus,  one,  lo- 
culus,  partition.  Having  but  one 
chamber  or  compartment. 

U'NIO — Lat.  A  pearl.  A  genus  of 
mussels. 

UNIONES — plur.  of  unio. 

UNSTRATIFIED — Not  stratified. 

UPHEAVAL — (p.  99). 

UPTILTED — Tilted  up  ;  raised  at  one 
end. 

URSUS — Lat     A  bear. 

VALLEYS  OF  DISLOCATION — (p.  164). 

VALLETS   OF  ELEVATION — (p.  161). 

VA'RIANS  —  Lat.  Varying,  chang- 
ing. 

VAS'CULAR — Containing   numerous 


VEGETATIVE  LIFE  —  Life  of  nutrition. 
VEGETABLE  EARTH  —  (p.  14). 
VEINS—  (p.  118). 
VE'NERICA'RDIA  —  fr.Venus,  and  ca'r- 

dium.     A  genus  of  bivalve  mol- 

lusks. 
VENTRICO'SA  —  Lat.    Ventricose  ;  in- 

flated, swelled  in  the  middle. 
VE'RTEBRA  —  fr.  lat.  vertere,  to  turn. 

A  joint  or  bone  of  the  spine. 
VE'RTEBRA  —  Plur.  of  vertebra. 
VE'RTEBRAL  COLUMN  —  The  spine  or 

back-bone. 
VER'TETBATE  —  Having  vertebrae,  or 

a  spine. 
VESICULA'RIS  —  Lat.  Vesicular  ;  con- 

taining vesicles. 
VI'RGULA  —  Lat.     A  little  rod. 
VI'RIDIS  —  Lat.     Green. 
VI'TREOCS  —  fr.  lat.  vitrea,  glass.  Re- 

sembling glass. 
VI'TREO-HES'INOUS  —  Partaking  of 

the  nature  of  glass  and  resin. 
VO'LATILE  —  fr.  lat.  volo,  I  fly.  Capa- 

ble of  assuming  the  state  of  vapour, 

and  flying  off. 
VOLA'TILIZE  —  To  become  volatile. 


VOLGA  'NIC  —  Relating  to  a  volcano. 


GLOSSARY.  — GEOLOGY. 


235 


VOLT'ZIA — A  genus  of  fossil  co'nifers. 
VOIU'TA — Lat.     A  whorl.    A  genus 

of  gasteropods. 
VO'SGEAN  —  Belonging  or  relating  to 


VULGA'RIS — Lat.     Common. 
WAL'CHIA — A  genus  of  fossil  co'nifers 

(p.  43). 
WEALD  —  Name  of  a  part  of  Kent 

and  Surrey  in  England. 
WEALDEIT  DEPOSIT — (p.  69). 


WHINSTONE —  A  Scotch  name  for 
greenstone  and  other  trap  rocks. 

ZA'MIA — fr.  gr.  zemia,  loss  or  damage. 
A  genus  of  the  order  Cyca'dese  plants. 

ZECHSTEIIT  —  Ger.  A  magnesian 
limestone,  lying  under  the  red 
standstone. 

ZO'OPHTTE — fr.  gr.  zoon,  an  animal, 
phuton,  plant.  A  plant-animal, 
which  seemingly  partakes  of  the  pro- 
perties of  both  plants  and  animals. 


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This  interesting  series  of  books  has  already  met  with  the  most 
flattering  reception  ever  extended  to  any  work  issued  from  the  Amer- 
ican press.  Introduced  into  the  Public  Schools  of  Pennsylvania,  and 
in  nearly  all  the  first  class  seminaries  of  learning  in  the  United  States. 


RECOMMENDATORY    NOTICES. 

"  Ruscbenberger's  Series  of  Boohs  on  Natural  History,  are  among  the 
most  valuable  and  useful  works,  for  the  use  of  Schools  that  have  ever  been 
published.  A  knowledge  of  Natural  History,  is  not  only  valuub'e,  but 
deeply  interesting-;  and  no  one's  education  can,  with  such  faciliiies  as  these 
works  afford,  be  considered  complete  without  it." — Nntional  Intelligencer. 

"These  are  the  mo-t  valuable  additions  of  the  day  to  our  stock  of  School 
Books.  The  avidiiy  with  which  they  have  been  seized  upon  is  unprece- 
dented. Though  the  first  vol.  was  published  for  the  first  time  only  a  few 
months  ago,  it  has  already  gone  through  its  fifth  edition;  the  second  is  fol- 
lowing  close  upon  its  heels;  and  the  third  prorni  es  even  to  be  more  popular 
than  either  of  the  other  two.  These  books  have  been  adopted  by  the  *  hoyal 
Council  of  Public  Instruction,'  for  the  use  of  Schoo's  throughout  France. 
They  are  recommended  and  have  been  adopted  by  some  of  the  most  emi 
nent  teachers  in  the  United  States." — Southern  Literary  Messenger. 

From  "  The  Ladies'  Companion,  a  Monthly  Magazine."  June,  1842,— New  York. 
W.  Snowden,  109,  Fulton  Street. 

"RuscHENBERGEn'a  ORNITHOLOGY:  Grigg  &  Elliot.  This  is  an  excel, 
lent  book,  by  one  who  shows  himself  perfectly  qualified  for  the  task  he  has 
undertaken,  which  is  the  publishing  of  a  series  of  works  on  the  different 
branches  of  education,  for  the  use  of  schools  and  colleges.  The  present 
issue  is  a  general  and  synoptical  view  of  Ornithology,  one  of  the  most 
interesting  subjects  in  Natural  History,  and  will  be  found  of  great  service, 
both  to  teacher  and  student." 

"  This  is  a  compendious,  and,  as  it  seems  to  us.  a  judiciously  compiled 
treatise  on  Ornithology,  and  one  well  calculated  for  the  use  of  Schools ;  for 
which  object  it  is  intended." — N.  Y.  Courier  and  Enquirer. 

"  In  the  work  before  us,  the  plan  is  happily  carried  out.  In  its  small 
compass  it  embraces  an  immense  amount  of  useful  and  interesting  infor- 
mation."— Buffalo  Adv.  and  Journal. 

"Ornithology. — This  is  evidently,  like  its  predecessors,  an  excellent  work 
of  instruction;  and  ha-s  been,  in  all  respects  well  got  up  by  the  publishers." 
— Pennsylvanian, 

"A  valuable  little  work, and  is  divided  up  and  classified  admirably.  The 
glossary,  giving  the  derivation  of  the  names  of  birds,  is  of  itself  worth  the 
price  of  the  volume." — New  York  Aurora. 

"An  exceedingly  interesting,  and  very  instructive  book,  and  one  which 
possesses  special  Attraction  for  young  ludies." — Baltimore  Sun. 

"RusciiENBKRGER's  SERIES  :  Second  BooTf. — A  highly  useful  and  instructive 
school  book.  Third  Book, — This  we  consider  as  decidedly  an  acquisition 
to  our  list  of  school  books,  the  subject  is  treated  of  in  such  a  plain  style  as 
to  be  adapted  to  the  simplest  capacity.  Altogether  we  think  the  above 
series  as  worthy  to  take  a  high  and  permanent  place  among  our  school 
books  " — Buffalo  Democrat. 

"  We  wish  we  could  induce  our  teachers  generally  to  examine  this,  as 
well  as  the  earlier  works  of  Dr.  Ruschenberger ;  they  are  admirably 
arranged,  and  just  the  very  books  needed  for  schools.  The  work  before 
us  on  the  Natural  History  of  Birds  is  an  admirable  one,  and  no  teachel 
•liould  neglect  to  introduce  the  series. ' — Cincinnati  Gazette. 

"It  is  an  excellent  text  book  of  an  interesting  science,  comprising  much 
knowledge  in  a  brief  space,  presented  in  a  clear  style  and  with  lucid 
arrangement.  Dr.  Rnschenbergcr,  who  has  already  achieved  a  high  charac 
icr  in  the  literary  world,  is  acquiring  additional  claims  by  his  exertions  i» 
the  field  of  Natural  Science.—  Spectator,  Washington  City. 


RECOMMENDATORY   NOTICES. 

u  Ruschenberger's  Series. — These  volumes  are  constructed  upon  a  new 
and  admirable  plan,  combining  great  simplicity  of  arrangement,  with  a 
perspicuity  and  sententiousness  of  style  seldom  found  in  works  of  this 
class;  and  which  has  elicited  the  highest  encomiums  of  upwards  of  thirty 
of  the  leading  professors  of  the  country,  whose  opinions  have  again  been 
endorsed  by  most  of  the  public  prints." — U.  Slates  Adv. 

"The  developement  of  the  principles  of  classification,  is  among  the  very 
best  we  have  ever  seen.  Science  is  here  dressed  in  her  own  native  sim- 
plicity and  beauty,  so  that  the  philosopher  may  admire,  while  the  child  may 
acquire  it. — Medical  Reporter. 

"  It  is  a  choice,  and  well  digested  work." — Atlas. 

"  An  excellent  publication  adapted  to  the  youthful  mind,  and  a  great  help 
to  the  mure  matured." — Mercury. 

"The  study  of  Natural  History  though  generally  neglected  in  schools, 
is  of  undoubted  use  :  the  present  work  contains  a  great  amount  of  infor. 
mation  within  a  small  compass,  and  properly  condenses  it  for  the  young 
mind."—  N.  Y.  Journal  of  Commerce. 

"  Ruschenberger's  Series. — The  subjects  are  Well  treated,  and  from  the 
exceediiig  cheapness,  and  admirable  arrangt  meu;  of  these  elementary  works, 
they  are  well  fitted  for  general  use  in  public  schools  and  academies." — 
New  York  American. 

"  We  do  not  hesitate  to  say,  that  this  is  the  best  work  of  the  kind  and 
dimensions,  that  has  even  fallen  under  our  notice.  We  hope  all  will  embrace 
the  first  opportunity  of  procuring  a  copy,  as  we  are  sure  they  will  prize 
it  highly." — Botanic  Recorder. 

"  A  well  digested  and  curefu'ly  arranged  abstract  of  the  most  interesting 
parts  of  Natural  Science." — Philadelphia  Gazette 

"  Admirably  adapted  to  convey  an  elementary  knowledge  on  the  subject 
of  which  it  treats;  and  will  be  found  an  excellent  book  for  the  student." — 
Public  Ledger. 

"  Valuable  in  every  respect, — it  contains  a  vast  amount  of  information, 
condensed  into  an  available  form,  for  the  use  of  schools." — Spirit  of  the  Times, 

"Just  such  a  work  as  is  wanted  for  elementary  instruction,  in  this  pleas- 
ing  branch  of  science." — New  York  Evening  Post. 

"  We  regard  this  series  as  eminently  useful,  supplying  adequately  the 
instruction  in  natural  history  necessary  to  a  proper  school  education." — 
North  American. 

"  It  is  an  excellent  little  work  for  the  purpose  designed,  written  in  a  cl  ar 
and  familiar  style,  and  will  not  fail  to  facilitate  the  studies  of  those  who 
wish  to  make  themselves  acquainted  with  the  subject." — Saturday  Courier. 

"Admirably  adapted  for  elementary  instruction." — Saturday  Chronicle. 

"  We  have  great  pleasure  in  recommending  it  as  an  excellent  elementary 
manual  on  the  subject  " — Medical  Examiner. 

"Ornithology — This  book  is  equal  in  merit  to  the  first  and  second,  and 
is  a  most  valuable  work.  It  is  intended  for  the  use  of  schools  and  acade- 
mies, and  we  would  call  the  attention  of  parents  and  others  to  the  series  of 
books  to  which  this  belongs,  assuring  them  at  the  same  time,  that  it  will 
answer  the  purpose  for  which  it  is  intended,  better  than  any  other  work  of 
the  kind  that  we  ever  saw,  or,  in  our  opinion,  that  was  ever  published  in 
this  country.  It  is  divided  into  questions  and  answers,  contains  an  exten- 
sive and  valuable  Glossary,  and  is  illustrated  by  eight  Plates  ;  and  what  is 
more  the  price  is  so  very  low  that  every  person  can  aflord  to  purchase  it.— 
Yoik  New  Era. 

.T~:  4 


NEW    SERIES 

OF 

ENGLISH    SCHOOL    BOOKS. 

PUBLISHED  AND  FOR  SALE  BT 

GRIGG    &    ELLIOT, 

NO.  9  NORTH  FOURTH  STREET,  PHILADELPHIA. 

And  for  Sale  by  Booksellers  and  Country  Merchants  generally  in  the  U.  S. 


To  Teachers,  Principals  and  Controllers  of  Schools,  Academies 
and  Colleges  throughout  the  United  States. 


Philadelphia,  9  North  Fourth  Street. 

SIR: — Believing  that  you  take  an  interest  in  educational  im- 
provements, we  beg  leave  to  call  your  attention  to  an  admirable 
series  of  School  Books  on  Natural  History,  prepared  by  Dr.  Rus- 
chenberger.  There  have  hitherto  been  few  works,  if  any,  on  this 
subject,  suited  to  the  capacity  of  pupils  at  an  early  age.  The 
series  referred  to  has,  therefore,  met  with  a  most  cordial  reception 
throughout  the  country,  from  teachers,  naturalists,  and  men  of 
letters.  The  volumes  are  eight  in  number — the  first  being  de- 
voted to  Anatomy  and  Physiology ;  the  second  to  Mammalogy ; 
the  third  to  Ornithology ;  the  fourth  to  Herpetology  and  Ichthy- 
ology ;  the  fifth  to  Conchology ;  the  sixth  to  Entomology ;  the 
seventh  to  Botany ;  and  the  eighth  to  Geology.  They  are  small  in 
size,  extremely  cheap,  as  accurate  in  scientific  arrangement  as  the 
most  voluminous  works  on  similar  subjects,  and  in  every  respect 
such  as  intelligent  parents  would  wish  to  place  in  the  hands  of 
their  children.  Each  work  is  entirely  independent  of  the  others. 
The  retail  price  is  only  fifty  cents  per  volume  for  the  first  seven 
volumes.  Orders  sent  to  us  directly,  or  through  any  bookseller, 
or  country  merchant,  will  be  promptly  attended  to. 

Respectfully,  your  obedient  servants, 

GRIGG  &  ELLIQT. 
1 


CRICC   &   ELLIOT, 

Publish  the  following  valuable  list  of  SCHOOL  BOOKS,  which  consti- 
tute a  regular  series  of  ELEMENTARY  WORKS,  designed  for  the  use  of 
COLLEGES,  ACADEMIES,  and  SCHOOLS,  also  for  family  use. 

The  publishers  hope  that  all  TEACHERS  who  have  their  pupils'  in- 
terest at  heart,  will  examine  these  valuable  series  of  School  Books  before 
introducing  any  others;  and  they  particularly  request  that  all  TEACHERS 
and  DIRECTORS  of  our  PUBLIC  SCHOOLS  in  the  various  states  will 
examine  G.  &  E.'s  new  SERIES  of  COMMON  SCHOOL  READERS, 
and  their  other  School  Books  before  introducing  any  others. 

TO   TEACHERS  AND  SCHOOL   COMMITTEES, 

RUSCHENBERGER'S  popular  series  of  SCHOOL  BOOKS  on  Natural 
History,  prepared  for  the  use  of  Schools,  by  Dr.  W.  S.  W.  Ruschenberger, 
from  the  text  of  Milne,  Edwards,  &c. 

1,  Elements  of  Anatomy  and  Physiology,  -  -      45  cuts. 

2,  Elements  of  Mammalogy,        -  -  -  -  75     " 

3,  Elements  of  Ornithology,        -  -  -  -  81     " 

4,  Elements  of  Herpetology  and  Ichthyology,     •  -  66    " 

5,  Elements  of  Conchology,        -  -  -  v(        -     119     •' 

6,  Elements  of  Entomology,        -  -  -  -  -      91     " 

7,  Elements  of  Botany,    -  -  -  -  -  -     194    " 

8,  Elements  of  Geology,  about    -  -  -  -  -    300    " 

Each  book  of  the  series  is  complete  in  itself,  and  has  a  full  glossary  ap- 
pended. The  illustrations  are  numerous,  and  beautifully  executed.  Teach- 
ers are  respectfully  invited  to  call  and  examine  these  works  before  selecting 
for  their  schools  any  books  on  Natural  History,  these  being  very  cheap,  and 
having  been  approved  by  distinguished  and  scientific  men. 

Among  the  very  numerous  notices  received  from  all  parts  of  the  United 
States,  the  publishers  subjoin  the  following: — 

"  We  have  no  handbooks  equal  to  these,  and  we  think  Dr.  R.  has  con- 
ferred an  obligation  upon  teachers  and  learners,  by  producing  them  in  an 
English  dress,  with  all  the  advantages  of  well  engraved  illustrations.  The 
whole  set  of  this  work,  which  is  furnished  at  a  low  price,  will  prove  an  in- 
valuable acquisition  to  the  school  library." 

"  Dr.  Ruschenberger' s  series  of  books  on  Natural  History. — We  have  hastily 
glanced  over  the  first  four  numbers,  and  have  profited  much  by  their  peru- 
sal. Besides  being  a  complete  system,  the  different  subjects  are  treated  in 
a  concise  and  elegant  style  by  the  author.  The  work  is  peculiarly  adapted 
to  the  use  of  our  District  Schools,  and  when  we  see  this  important  branch 
of  general  education  so  much  neglected,  we  would  urge  upon  our  directors 
to  examine  Dr.  Ruschenberger's  Series,  and  place  it  where  in  justice  it 
should  be,  in  every  district  school  in  the  country." 

"These  4 First  Books1  of  D*r.  R.  have  been  everywhere  received  with 
great  and  deserved  commendation,  and  they  will  be  found  well  to  merit  the 
attention  of  teachers  throughout  the  United  States,  as  furnishing  a  means 


GRIGG  &  ELLIOT'S  SCHOOL  BOOKS.  3 

of  instruction  not  otherwise  to  be  met  with,  upon  subjects  of  the  utmost 
importance  to  a  course  of  liberal  education. 

"  We  have,  from  the  same  publishers,  a  set  of  their  series  of  '  Common 
School  Readers'1 — four  in  all,  arranged  progressively — of  which,  we  under- 
stand, that  no  less  than  70,000  have  been  sold  in  a  short  period,  a  fact 
affording  conclusive  evidence  of  the  estimation  in  which  these  reading 
books  are  held.  These  volumes  are  so  arranged  as  to  bring  the  learner 
forward  from  matters  of  simple  information  to  subjects  of  high  interest  in 
morals  and  history,  and  are  well  calculated,  not  only  to  instruct  at  the 
time,  but  likewise  to  create  a  fondness  for  the  acquisition  of  knowledge." 

"Our  Booksellers  have  just  received  complete  sets  of  Dr.  Ruschenber- 
ger's  elementary  works  on  Natural  History,  for  ihe  use  of  schools  and  col- 
leges, and  to  which  we  would  call  the  attention  of  those  having  the  instruc- 
tion of  our  youth  in  charge.  The  style  of  the  author  appears  to  be  clear 
and  succinct,  and  the  various  subjects  are  illustrated  by  appropriate  draw- 
ings. We  learn  that  Dr.  R.'s  works  have  been  introduced  into  the  public 
schools  of  Pennsylvania,  Ohio,  .Mississippi,  and  other  States,  and  in  nearly 
all  the  first  class  seminaries  of  learning  in  the  United  States,  and  have 
always  met  with  a  reception  truly  flattering. 

"In  addition,  they  have  for  sale  Grigg~&  Elliot's  new  series  of  Com- 
mon School  Readers.  We  have  not  time  to  examine  them  thoroughly,  but 
to  judge  from  the  many  encomiums  they  have  received  from  the  high- 
est sources,  we  should  think  they  were  destined  to  occupy  a  high  place 
in  the  esteem  of  those  interested  in  the  cause  of  education."— New  Orleans 
Picayune,  Jan.  4,  1845. 

New  and  Valuable  School  Books. — "  In  view  of  the  long  list  of  recommen- 
dary  notices  by  many  of  the  most  distinguished  teachers  in  the  Union,  and 
by  a  cursory  examination  ourselves,  we  can  cheerfully  declare  thai  no 
TEACHER  or  SCHOOL  should  be  without  this  series  of  school  books. 
We  invite  all  those  interested  to  call  at  Davis'  and  examine  them,  where 
they  are  for  sale,  wholesale  and  retail  at  very  low  prices." — Indiana  State 
Journal,  Indianapolis. 

"Messrs.  Grigg  &  Elliot,  Philadelphia,  have  published  an  interesting 
series  of  books,  which  we  commend  to  the  attention  of  TEACHERS.  A 
series  of  Readers,  adapted  to  successive  classes,  which  seem. to  us  well  se- 
lected and  arranged.  A  far  more  important  series,  and  one  long  called  for, 
in  the  shape  of  elementary  scientific  treatises  on  the  following  subjects: 
Mammalogy,  Ornithology,  Herpetology  and  Ichthyology,  Botany,  Concholo- 
gy,  Anatomy  and  Physiology,  and  Geology.  These  works  are  prepared  by 
Dr.  Ruschenberger,  on  the  plan  and  materials  of  similar  books  used  in  Ihe 
public  schools  of  France.  They  are  illustrated  with  the  necessary  plates, 
and  are  complete  in  their  treatment  of  the  subject,  and  undoubtedly  deserve 
a  place  in  our  now  meagre  list  of  elementary  class  books  of  science.  These 
works  are  for  sale  by  M'Carter&  Allen,  Charleston,  S.C.,  Allen,  M'Carter  & 
Co.,  Columbia,  and  Thomas  Richards,  Augusta,  Ga."— Charleston  Mercury. 

The  publishers  have  just  received,  for  one  school,  in  Bangor,  Maine,  an 
order  for  seventy-five  copies  each  of  the  above  valuable  works,  which  is  an 
evidence  of  the  high  estimation  in  which  they  are  held  in  that  section  of 
country,  by  some  among  the  best  teachers  in  New  England. 


4  GRIGG  &  ELLIOT'S  SCHOOL  BOOKS. 

Portland,  August  22,  1845. 

DEAR  SIR  : — Your  note,  accompanying  Dr.  Ruschenberger's  Elementary 
Books  on  Natural  History,  for  the  use  of  schools,  &c.,  was  duly  received, 
for  which  please  accept,  for  yourself  and  the  publishers,  my  sincere  thanks. 

Having  examined  several  of  the  volumes,  I  take  great  pleasure  in  ex- 
pressing my  approbation  of  the  work.  It  is  better  adapted  to  the  purposes 
of  elementary  instruction  than  any  other  cheap  work  with  which  I  am  ac- 
quainted. 

Among  its  many  merits  I  regard  that  of  the  constant  adherence  of  the 
author  to  the  language  of  science  as  peculiarly  worthy  of  notice.  Although 
the  descriptions  of  the  various  objects  treated  of  may  appear  obscure  at 
first  sight,  every  difficulty  is  removed  by  the  copious  glossary  which  ac- 
companies each  volume.  While  the  student  is  acquiring  accurate  instruc- 
tion in  natural  history,  he  is,  at  the  same  time,  and  with  no  additional 
labour,  adding  essentially  to  his  vocabulary. 

With  these  remarks  I  would  most  cordially  recommend  the  work  as  well 
adapted  to  fulfil  the  objects  for  which  it  is  published. 

With  much  respect  yours  truly, 

J.  W.  M1GHELS, 

Member  of  the  Natural  History  Societies  in  Boston  and  Portland,  also  of  the 
American  Association  of  Geologists,  <S(-c.  <fc.  4~c. 

Brunswick,  Maine,  Sept.  19,  1845. 

Our  schools  have  long  felt  a  want  of  suitable  text  books  on  the  several 
branches  of  Natural  History;  but  this  desideratum  has  been  happily  sup- 
plied by  Dr.  Ruschenberger's  series,  published  by  Messrs.  Grigg  &  Elliot, 
of  Philadelphia. 

These  truly  scientific,  yet  cheap  works,  can  scarcely  fail  of  diffusing  a 
more  extended  taste  for  those  too  long  neglected  branches  of  education, 
•which,  when  properly  pursued,  will  breathe  new  life  and  vigour  into  our 
systems  of  education. 

Elementary  works  on  Natural  History  are  too  often  spoiled  by  an  attempt 
to  divest  them  of  scientific  terms,  thus  rendering  the  simple  and-determi- 
nate  language  of  science  a  confused  and  unmeaning  gibberish.  But  these 
works  are  a  noble  exception,  simple  in  their  arrangement,  and  precise  in 
their  definitions.  Professor  PARKER  CLEAVELAND,  LL.  D. 

Bowdoin  College,  Brunswick,  Maine. 

I  heartily  concur  in  the  above  opinion  of  Dr.  R.'s  works,  and  shall  use 
my  influence  to  have  them  introduced  to  Brunswick  Seminary. 

Yours  truly, 

G.  C.  SWALLOW,  A.  M. 
Principal  Brunswick  Academy,  Brunswick,  Maine. 

Portland,  Aug.  21,  1845. 

DEAR  SIRS  : — Dr.  Ruschenberger's  series  of"  First  Books  of  Natural  His- 
tory" is  a  most  valuable  acquisition  to  all  classes  of  readers,  especially  to 
the  young. 

These  classics,  admirable  in  their  whole  structure  and  composition,  will 
date  a  new  era  in  the  facilities. to  useful  instruction  in  the  schools  of  our 
country. 


GRIGG  &  ELLIOT'S  SCHOOL  BOOKS.  5 

Though  closed  is  my  course  of  thirty-five  years  teaching,  I  am  tempted 
to  begin  the  work  anew  with  these  delightful  books  as  auxiliaries.  They 
should  be  in  the  HANDS  OF  ALL  TEACHERS  who  can  instruct,  and  all 
pupils  who  can  learn.  Yours  most  truly, 

B.  CUSHMAN,  A.  M. 
Portland,  late  Principal  of  the  Academy. 

Illinois  College,  Sept.  5,  1845. 

It  is  three  years  since  I  first  became  acquainted  with  Ruschenberger's 
Series  of  First  Books  of  Natural  History,  and  I  have  examined  those  of  the 
series  which  have  appeared  since  that  time.  I  have  also  used  these  books 
in  the  instruction  of  my  classes  in  college,  and  I  am  happy  to  state  that  I 
consider  them  as  vastly  superior,  for  the  purposes  of  instruction,  to  any 
book  or  series  of  books  on  the  same  subject  in  our  language.  I  take  plea- 
sure, therefore,  in  expressing  the  opinion  that  the  extensive  introduction  of 
these  books  into  the  courses  of  instruction  in  the  Colleges  of  the  United 
States  would  prove  of  incalculable  advantage  to  the  progress  of  sound  edu- 
cation among  us. 

SAMUEL  ADAMS,  M.  D. 

.     Professor  of  Chemistry  and  Natural  History,  Illinois  College. 
I  cheerfully  concur  in  the  opinion  which  Dr.  Adams  has  expressed,  and 
shall  use  the  influence  I  may  have  to  facilitate  the  introduction  of  these 
works  into  SCHOOLS  and  PUBLIC  SEMINARIES. 

J.  M.  STURTEVAXT, 
Jacksonville,  Sept.  8,  1845.  President  of  Illinois  College. 

Pa.  Literary,  Scientific,  and  Military  Collegiate  Institute. 
GEKTLEMEN : — I  have  examined,  with  attention,  the  First  Books  of  Natu- 
ral History,  by  Dr.  Ruschenberger,  and  unhesitatingly  express  my  appro- 
bation of  its  superior  merits.  I  think  it  well  adapted  to  the  wants  of  our 
Seminaries  of  Learning  generally,  and  that  it  should  also  constitute  a  part 
of  every  private  library.  As  such,  I  confidently  recommend  it  to  the  pa- 
tronage of  an  enlightened  public. 

A.  PARTRIDGE, 

Pres.  of  the  Pa.  L.  S.  M.  C.  Institute. 
Messrs.  GRIGG  &  ELLIOT,  Philadelphia. 

Woodward  College,  Cincinnati,  Ohio. 

GENTLEMEN  : — I  have  examined  Dr.  Ruschenberger's  series  of  school 
books  in  the  different  branches  of  Natural  History.  The  volumes  are,  in 
every  respect,  exceedingly  well  got  up,  and  their  cheapness  will  place 
them  within  the  reach  of  all  classes. 

It  is  judged  expedient  to  introduce  the  subject  of  Natural  History  amo'ng 
the  studies  of  our  Common  Schools.  I  know  not  a  work  so  well  adapted  as 
Dr.  Ruschenberger's,  not  only  by  its  plainness  of  style,  but  by  its  numerous 
and  excellent  engravings.  The  last  are  essential  to  the  understanding  of 
such  works,  and  yet  their  cost  has  hitherto  been  so  great  as  to  exclude  them 
from  common  schools. 

The  division  into  volumes,  each  embracing  one  department  of  Natural 
History,  gives  the  present  decided  advantage^  over  most  other  productions 
of  a  similar  character. 

B.  P.  AYDELOTT. 


6  GRIGG  &  ELLIOT'S  SCHOOL  BOOKS. 

"  Ruschenberger's  Series  of  Books  on  Natural  History,  are  among  the 
most  valuable  and  useful  works,  for  the  use  of  schools  that  have  ever  been 
published.  A  knowledge  of  Natural  History,  is  not  only  valuable,  but 
deeply  interesting;  and  no  one's  education  can,  with  such  facilities  as  these 
works  afford,  be  considered  complete  without  it." — National  Intelligencer. 

"These  are  the  most  valuable  additions  of  the  day  to  our  stock  of  School 
Books.  The  avidity  with  which  they  have  been  seized  upon  is  unprece- 
dented. Though  the  first  vol.  was  published  for  the  first  time  only  a  few- 
months  ago,  it  has  already  gone  through  its  fifth  edition  ;  the  second  is  fol- 
lowing close  upon  its  heels;  and  the  third  promises  even  to  be  more  popu- 
lar than  either  of  the  other  two.  These  books  have  been  adopted  by  the 
'Royal  Council  of  Public  Instruction,' for  the  use  of  Schools  throughout 
France.  They  are  recommended  and  have  been  adopted  by  some  of  the 
most  eminent  teachers  in  the  United  States." — Southern  Literary  Messenger. 

"This  is  a  compendious,  and,  as  it  seems  to  us,  a  judiciously  compiled 
treatise  on  Ornithology,  and  one  well  calculated  for  the  use  of  Schools;  for 
which  object  it  is  intended." — N.  Y.  Courier  and  Enquirer. 

"RUSCHEXBERGER'S  SERIES:  Second  Book. — A  highly  useful  and  instruct- 
ive school  book.  Third  Book. — This  we  consider  as  decidedly  an  acquisi- 
tion to  our  list  of  school  books;  the  subject  is  treated  of  in  such  a  plain 
style  as  to.be  adapted  to  the  simplest  capacity.  Altogether  we  think  the 
above  series  as  worthy  to  take  a  high  and  permanent  place  among  our 
school  books." — Buffalo  Democrat. 

"We  wish  we  could  induce  our  teachers  generally  to  examine  this,  as 
well  as  the  earlier  works  of  Dr.  Ruschenberger ;  they  are  admirably  ar- 
ranged, and  just  the  very  books  needed  for  schools.  The  work  before  us 
on  the  Natural  History  of  Birds  is  an  admirable  one,  and  no  teacher  should 
neglect  to  introduce  the  series." — Cincinnati  Gazette. 

"  Ruschenberger*  s  Series. — The  subjects  are  well  treated,  and  from  the 
exceeding  cheapness  and  admirable  arrangements  of  these  elementary 
works,  they  are  well  fitted  for  general  use  in  public  schools  and  acade- 
mies."— New  York  American. 

"  We  do  not  hesitate  to  say,  that  this  is  the  best  work  of  the  kind  and 
dimensions,  that  has  ever  fallen  under  our  notice.  We  hope  all  will  em- 
brace the  first  opportunity  of  procuring  a  copy,  as  we  are  sure  they  will 
prize  it  highly." — Botanic  Recorder. 

"Admirably  adapted  to  convey  an  elementary  knowledge  on  the  subject 
of  which  it  treats;  and  will  be  found  an  excellent  book  for  the  student." — 
Public  Ledger. 

"Valuable  in  every  respect, — it  contains  a  vast  amount  of  information, 
condensed  into  an  available  form  for  the  use  of  schools." — Spirit  of  the 
Times. 

"  Just  such  a  work  as  is  wanted  for  elementary  instruction,  in  this  pleas- 
ing branch  of  science." — New  York  Evening  Post. 

"We  regard  this  series  as  eminently  useful,  supplying  adequately  the 
instruction  in  natural  history  necessary  to  a  proper  school  education."— 
North  American. 

"It  has  been  justly  observed,  that '  the  double  effect  of  the  study  of  Natu- 
ral History  is  to  impart  certainty  to  the  mind,  and  religion  to  the  heart,'  and 


GRIGO  &  ELLIOT'S  SCHOOL  BOOKS.  7 

the  Christian  no  less  than  the  man  of  science,  must  rejoice  in  every  effort 
to  throw  more  widely  open  the  sublime  and  boundless  field  which  it  pre- 
sents. This  is  the  design  of  Dr.  Ruschenberger,  in  a  series  of  First  Books 
of  Natural  History,  which  he  is  preparing  for  the  use  of  schools  and  col- 
leges."— Banner  of  the  Cross. 

"  The  series  have  met  a  demand  and  sale  in  France  almost  unparalleled, 
and  the  works  are  well  adapted,  not  only  for  schools,  bat  for  popular  read- 
ing and  instruction.  This  work  is  fro.m  the  French  of  Edwards  and  Comte, 
and  has  received  the  warm  commendation  of  many  of  the  best  physicians 
and  scholars  in  this  country." — N.  York  Evening  Tattler. 

"It  is  highly  commended  by  the  very  best  authorities." — N.  Y.  Tribune. 

"This  book  is  highly  commended  by  competent  judges,  and  we  there- 
fore give  our  solemn  opinion  that  it  is  an  excellent  work." — Boston  Daily 
Times. 

"  We  have  examined  this  new  book  for  schools  and  colleges,  with  pecu- 
liar gratification.  The  style  is  succinct  and  clear,  and  the  subject  illus- 
trated by  appropriate  drawings.  We  should  be  glad  to  see  this  work 
introduced  into  all  the  schools.  It  teaches  knowledge  the  most  important, 
which  has  been,  however,  strangely  overlooked  in  our  school  and  college 
system.  It  is  a  book  which  should  not  be  confined  to  seminaries  alone.  It 
may  be  used  with  advantage  by  all  individuals  in  society.  We  repeat,  it 
is  in  all  respects  a  most  excellent  work,  and  we  hope  will  receive  the  at- 
tention and  patronage  it  merits." — Brooklyn  Evening  Star. 

"  We  are  highly  pleased  with  this  work.  For  elementary  instruction  in 
families,  schools  and  colleges,  it  is  decidedly  superior  to  anything  of  the 
kind  we  have  seen.  It  gives  much  valuable  information  in  a  very  small 
space,  and  in  style  it  is  generally  free  from  abstruse  technicalities.  It  has 
already  received  the  highest  recommendations  from  a  large  number  of 
professional  men  in  different  parts  of  the  country ;  and  it  must  have,  we 
think,  a  general  circulation.  It  gives  that  kind  of  knowledge  which  should 
be  diffused  among  the  mass  of  the  people,  and  it  must  and  will  be  patron- 
ized as  far  as  its  merits  are  known."— Zion's  Watchman. 

"This  is  a  most  valuable  work,  by  Dr.  Ruschenberger,  and  most  ad- 
mirably are  the  plates,  representing  all  the  different  parts  of  the  body,  done. 
It  is  cheap,  and  every  parent  should  place  one  in  the  hands  of  their  chil- 
dren."— N.  Y.  Herald. 

"We  have  examined  this  little  volume  with  much  pleasure,  and  think  it 
admirably  adapted  to  the  purpose  for  which  it  is  intended.  Animal  me- 
chanism, as  a  study,  has  generally  been  neglected,  except  by  the  few,  whose 
profession  requires  a  knowledge  of  it,  and  who  have  time  to  spare  in  ac- 
quiring that  knowledge.  A  prominent  cause  of  the  neglect  of  this  useful 
and  interesting  science  by  the  general  student,  is  the  want  of  a  suitable 
treatise  upon  the  subject,  those  extant  being  too  voluminous,  technical,  and 
expensive  for  general  use.  The  little  work  before  us  is  happily  calculated 
to  supply  this  want.  It  will,  we  think,  be  introduced  into  our  schools  and 
colleges  as  a  text-book,  but  its  circulation  ought  not  to  be  confined  there. 
Every  private  library  should  be  considered  incomplete  without  it." — N.  Y. 
Mechanic. 

"It  seems  to  us  to  be  well  suited  for  the  object  for  which  it  is  designed, 
and  it  will  doubtless  be  introduced  into  many  of  our  elementary  schools." 
— The  American  Journal  of  the  Medical  Sciences. 


8  GRIGG  &  ELLIOT'S  SCHOOL  BOOKS. 

"The  plan  and  arrangement  of  the  work  are  admirable,  and  eminently 
calculated  to  facilitate  the  progress  of  the  pupil.  We  recommend  it  to 
teachers  and  heads  of  families."— Philadelphia  Sat.  Chronicle. 

"We  cannot  too  earnestly  recommend  it  to  public  attention." — Cincin- 
nati Enquirer. 

"The  reputation  of  the  author  is  a  guarantee  that  the  work  is  a  good  one. 
On  examination  w^  find  it  to  be  so.  It  is  an  admirable  compend  of  the 
subjects  of  which'it  treats: — we  should  think,  indeed,  that  it  would  attract 
the  attention  of  teachers,  both  from  its  cheapness,  and  the  admirable  man- 
ner in  which  it  is  arranged." — Cincinnati  Gazette. 

"As  far  as  we  are  competent  to  determine,  it  may  safely  be  welcomed 
as  an  important  addition  to  the  means  of  elementary  instruction  in  natural 
science." — The  Friend. 

"  The  Second  Book: — This  number  treats  of  all  animals  that  in  infancy 
feed  on  the  milk  of  their  mothers ;  from  the  human  being  down  to  the  mus- 
quito-catching  bat.  Like  the  'First  Book,'  it  is  divided  into  questions  and 
answers,  and  a  glossary ;  and  is  illustrated  by  six  plates.  It  is  as  cheap  as 
dirt;  and  contains  an  abundance  of  useful  information.  There  are  thou- 
sands of  persons  in  this  country,  and  millions  in  Europe,  who  do  not  know 
that  whales  give  milk." — New  York  Era. 

"  The  series  of  books  of  which  this  forms  a  part  has  been  highly  and 
justly  commended  by  the  ablest  judges,  as  furnishing  rare  facilities  in  the 
acquisition  of  branches  of  knowledge,  but  too  much  neglected  in  our 
schools.  We  have  examined  the  volumes  with  much  care,  and  we  find 
them  well  deserving  all  the  praise  bestowed  on  them." — Godey's  Lady's 
Book. 

"  Dr.  Ruschenberger's  series  of  books  on  Natural  History  are  among  the 
most  valuable  and  useful  works  for  the  use  of  schools  that  have  ever  been 
published.  The  text  is  that  of  two  distinguished  French  Naturalists, 
Milne  Edwards  and  Achille  Comte— translated  and  prepared  for  the  use 
of  schools  and  colleges  by  Dr.  Ruschenberger,  who  deserves  great  credit 
for  thus  devoting  his  leisure  to  so  useful  an  object.  A  knowledge  of  Na- 
tural History  is  not  only  valuable,  but  deeply  interesting,  and  no  one's  edu- 
cation can,  with  such  facilities  as  are  now  offered,  be  considered  complete 
without  it.  Simple  and  comprehensive  as  the  elements  of  this  science 
have  been  made  by  the  French  professors  and  Dr.  R.,  and  adopted  as  they 
should  be,  in  schools  and  colleges,  it  would  be  inexcusable  in  any  youth  to 
be  ignorant  of  these  elements,  and  having  acquired  them  he  will  find  it 
equally  easy  and  pleasant  to  enlarge  his  knowledge  by  consulting  more 
extended  works,  and  devoting  his  attention  to  the  study  of  the  various 
branches  of  this  interesting  science.  The  present  book  on  Ornithology  is 
upon  the  same  plan  and  possesses  the  same  merit  as  those  that  have  pre- 
ceded it,  and  which  have  been  received  with  deserved  commendation.  It 
is  brief  and  comprehensive,  but  sufficiently  full  to  give  the  student  a  tho- 
rough knowledge  of  the  elements  of  Ornithology.  It  contains  also  a  Glos- 
sary of  the  terms  used  in  this  branch  of  Natural  History,  and  a  number  of 
wood  cuts  illustrative  of  the  matter  contained  in  the  body  of  the  work." — 
Washington  National  Intelligencer. 

"  We  have  much  pleasure  in  commending  this  series  of  works — the 
third  of  which  now  before  us,  is  on  Ornithology.  It  will  be  found  useful 
in  the  school-room,  or  the  private  .study ."—-17.  S.  Gaz. 


NEW  AND  IMPORTANT 

SCHOOL   BOOKS. 


TO  TEACHERS,  PRINCIPALS  AND  CONTROLLERS 


OF 


SCHOOLS,  ACADEMIES  AND  COLLEGES, 


SMILEY'S  ARITHMETICAL  RULES  AND  TABLES 
FOR  YOUNG  BEGINNERS. 

This  is  the  best  work  of  the  kind  now  in  print ;  but  teachers  are  particu- 
larly requested  to  examine  for  themselves. 

SMILEY'S  ARITHMETIC,  or  the  New  Federal  Calculator, 
in  dollars  and  cents.  This  work  contains,  among  other  important  im- 
provements, Questions  on  the  Rules  and  Theory  of  Arithmetic,  which  are 
considered  by  teachers  generally,  very  conducive  to  the  improvement  of 
the  pupil. 

Although  a  prejudice  exists  among  some  teachers  in  favour  of  the  old 
works  on  arithmetic,  yet  the  very  liberal  patronage  which  this  work  has 
received,  must  be  considered  as  decisive  evidence  of  the  great  estimation 
in  which  it  is  held  by  most  of  the  instructors  of  youth.  Upwards  of  300,- 
000  copies  have  been  printed  and  sold.  The  sums  being  altogether  in  dol- 
I-V.T  and  cents,  gives  it  a  decided  preference  over  any  other  arithmetic  in 
use.  The  most  distinguished  teachers  of  our  city  and  country  pronounce 
it  superior  to  any  other  like  work  ;  therefore  the  publisher  sincerely  hopes 
this  useful  improvement  will  overcome  the  prejudice  that  many  teachers 
have  to  introducing  new  works,  particularly  those  preceptors  who  wish  to 
discharge  their  duty  faithfully  to  parent  and  child. 

The  editors  of  the  New  York  Telegraph,  speaking  of  Smiley's  Arithme- 
1 


2  t      GRIGG  &  ELLIOT'S  SCHOOL  BOOKS. 

tic,  observe,  "  We  do  not  hesitate  to  pronounce  it  an  improvement  upon 
every  work  of  that  kind  previously  before  the  public,  and  as  such  recom- 
mend its  adoption  in  all  our  schools  and  academies." 

A  KEY  TO  THE  ABOVE  ARITHMETIC ;  in  which  all 
the  examples  necessary  for  a  learner  are  wrought  at  large,  and  also  solu- 
tions given  of  all  the  various  rules.  Designed  principally  to  facilitate  the 
labour  of  teachers,  and  assist  such  as  have  not  the  opportunity  of  a  tutor's 
aid.  By  T.  T.  Smiley,  author  of  the  New  Federal  Calculator,  &c.  &c. 

CONVERSATIONS   ON  NATURAL  PHILOSOPHY;   in 

which  the  Elements  of  that  Science  are  familiarly  explained.  Illustrated 
with  plates.  By  the  author  of"  Conversations  on  Chemistry,"  &c.  With 
considerable  additions,  corrections,  and  improvements  in  the  body  of  the 
work,  appropriate  Questions,  and  a  Glossary.  By  Dr.  Thomas  P.  Jones. 

CONVERSATIONS  ON  CHEMISTRY;  in  which  the  Ele- 
ments of  that  Science  are  familiarly  explained  and  illustrated  by  Experi- 
ments and  Engravings  on  wood.  From  the  last  London  edition.  In  which 
all  the  late  Discoveries  and  Improvements  are  brought  up  to  the  present 
time,  by  Dr.  Thomas  P.  Jones. 

The  learned  and  distinguished  Professors  Silliman  and  Bigelow,  speak- 
ing of  these  works,  observe: — "They  are  satisfied  that  the  Works  contain 
the  fundamental  principles,  and  truths  of  the  Sciences,  expressed  in  a  clear, 
intelligible,  and  interesting  manner,  and  that  the  present  editions  are  de- 
cidedly more  valuable  than  any  preceding  ones.  The  high  character  of 
the  author,  as  a  lecturer,  and  a  man  of  science,  will,  we  doubt  not,  secure 
for  these  Works  the  good  opinion  of  the  public,  and  cause  their  extensive 
adoption  among  Seminaries  and  Students." 

TEACHERS  in  ordering  would  do  well  to  say  "Jones'  Improved  Editions." 

THE  BEAUTIES  OF  HISTORY,  or  Examples  of  the 
Opposite  Effects  of  Virtue  and  Vice,  for  the  use  of  Schools  and  Families, 
with  Questions  for  the  Examination  of  Students.  1  vol.  12mo.,  with  plates. 

This  work  is  introduced  into  our  High  School.  It  is  particularly  adapted 
fora  Class  Book  in  all  our  male  and  female  Seminaries,  &c. 

"  We  have  received  from  the  publishers,  Messrs.  Grigg  &  Elliot,  a  very 
neat  duodecimo  volume,  entitled  'The  Beauties  of  History;  or,  Examples 
of  the  opposite  effects  of  Virtue  and  Vice,  drawn  from  real  life.'  After  a 
careful  examination  of  this  book,  we  can  conscientiously  recommend  it  to 
parents  and  teachers  as  a  most  meritorious  performance.  There  are  here 
collected,  within  a  narrow  compass,  the  most  striking  examples  of  indivi- 
dual virtue  and  vice  which  are  spread  forth  on  the  pages  of  history,  or  are 


GRIGG  &  ELLIOT'S  SCHOOL  BOOKS.  9 

recorded  in  personal  biography.  The  noblest  precepts  are  recommended 
for  the  guidance  of  youth ;  and  in  the  most  impressive  manner  is  he  taught 
to  conquer  the  degrading  impulses  which  lower  the  standard  of  the  human 
character.  We  have  not  lately  met  with  a  volume  which,  in  design  and 
execution,  seemed  so  acceptable  as  this.  The  book,  moreover,  is  hand- 
somely got  up,  and  illustrated  with  wood  engravings." 

GRIMSHAW'S  HISTORY  OF  THE  UNITED  STATES. 

Recently  brought  up  by  the  author  to  the  present  time. 

Also,  Questions  adapted  to  the  above  History ;  and  a  Key,  adapted  to  the 
Questions,  for  the  use  of  Teachers  and  Private  Families. 

GRIMSHAW'S  HISTORY  OF  ENGLAND.  Recently 
brought  up  by  the  author  to  the  present  time. 

Also,  Questions  adapted  to  the  above  History;  and  a  Key,  adapted  to  the 
Questions,  for  the  use  of  Teachers  and  Private  Families. 

GRIMSHAW'S  IMPROVED  EDITION  OF  GOLDSMITH'S 
HISTORY  OF  GREECE,  with  a  Vocabulary  of  the  Proper 

Names  contained  in  the  work,  and  the  Prosodial  Accents,  in  conformity 
with  the  pronunciation  of  Lempriere. 

Also,  Questions  adapted  to  the  above  History;  and  a  Key,  adapted  to  the 
Questions,  for  the  use  of  Teachers  and  Private  Families. 

GRIMSHAW'S  IMPROVED  EDITION  OF  GOLDSMITH'S 
HISTORY  OF  ROME,  revised  and  corrected,  and  a  Vocabulary 
of  Proper  Names  appended,  with  Prosodial  Marks  to  assist  in  their  pro- 
nunciation. 

Also,  Questions  adapted  to  the  above  History;  and  a  Key,  adapted  to  the 
Questions,  for  the  use  of  Teachers  and  Private  Families. 

GRIMSHAW'S  HISTORY  OF  FRANCE,  with  Key  and 
Questions. 

GRIMSHAW'S  HISTORY  AND  LIFE  OF  NAPOLEON. 

The  editor  of  the  North  American  Review,  speaking  of  these  Histories, 
observes,  that— "Among  the  Elementary  Books  of  American  History,  we 
do  not  remember  to  have  seen  any  one  more  deserving  approbation  than 
Mr.  Grimshaw's  History  of  the  United  States.  It  is  a  small  volume,  and  a 
great  deal  of  matter  is  brought  into  a  narrow  space ; — but  the  author  has 
succeeded  so  well  in  the  construction  of  his  periods,  and  the  arrangement 
of  his  materials,  that  perspicuity  is  rarely  sacrificed  to  brevity. 


4  GRIGG  &  ELLIOT'S  SCHOOL  BOOKS. 

"The  chain  of  narrative  is  skilfully  preserved,  and  the  author's  reflec- 
tions are  frequently  such  as  make  the  facts  more  impressive,  and  lead  the 
youthful  mind  to  observe  causes  and  consequences  which  might  otherwise 
have  been  overlooked.  As  a  school  book  it  may  justly  be  recommended. 

"What  has  been  said  of  this  volume  will  apply  generally  to  his  other 
historical  works.  They  are  each  nearly  of  the  same  size  as  the  one  just 
noticed,  and  designed  for  the  same  object,  that  is,  the  use  of  classes  in 
schools. 

"The  History  of  England  is  an  original  composition;  but  the  Grecian 
and  Roman  Histories  are  Goldsmith's,  improved  by  Mr.  Grimshaw,  in 
which  he  has  corrected  the  typographical  errors,  with  which  the  later  edi- 
tions of  Goldsmith's  Abridgments  so  much  abound;  and  removed  any 
grossness  in  language,  which,  in  some  few  instances,  render  these  valua- 
ble compends  less  useful  in  the  schools  to  which  youth  of  both  sexes  resort. 
He  has  also  added  a  Vocabulary  of  Proper  Names,  accentuated,  in  order 
to  show  their  right  pronunciation,  which  is  a  valuable  appendage  to  the 
History. 

"All  these  books  are  accompanied  with  very  full  and  well-digested 
Tables  of  Questions,  for  the  benefit  of  Pupils,  and  also  with  Keys  to  the 
same,  for  the  convenience  of  Teachers." 

[Teachers  generally,  who  have  examined  Mr.  Grimshaw's  Histories  of 
the  United  States  and  England,  and  Improved  Editions  of  Goldsmith's 
Greece  and  Rome,  have  given  them  a  decided  preference  to  any  other 
Histories  in  use  as  School  Books— and  any  person  who  will  examine  them, 
will  find  about  one  thousand  errors  in  each  corrected;  and  teachers  order- 
ing those  works  will  do  well  to  say  "  Grimshaw's  Improved  Editions."] 

GRIMSHAW'S  LADIES'  LEXICON,  and  Parlour  Com- 
panion ;  containing  nearly  every  word  in  the  English  language,  and  ex- 
hibiting the  plurals  of  nouns  and  the  participles  of  verbs,  being  also 
particularly  adapted  to  the  use  of  Academies  and  Schools.  By  William 
Grimshaw,  Esq.,  author  of  the  Gentlemen's  Lexicon,  &c. 

THE  GENTLEMEN'S  LEXICON,  or  Pocket  Dictionary; 
containing  nearly  every  word  in  the  English  language,  and  exhibiting  the 
plurals  of  nouns  and  the  participles  of  verbs;  being  also  particularly 
adapted  to  the  use  of  Academies  and  Schools.  By  William  Grimshaw, 
author  of  the  Ladies'  Lexicon,  History  of  England,  of  the  United  States,  &c. 

"  The  public  are  again  indebted  to  the  talents  of  Mr.  Grimshaw,  for  the 
very  useful  books  which  he  has  called  *  The  Ladies'  and  Gentlemen's 
Lexicon.'  The  peculiarity  and  advantages  of  these  works  may  be  col- 
lected from  the  following  portion  of  the  preface.  '  They  differ  from  all 


GRIGG  &  ELLIOT'S  SCHOOL  BOOKS.  5 

preceding  works  of  the  kind  in  this,  that  they  exhibit  the  plurals  of  all 
nouns  which  are  not  formed  by  the  mere  addition  of  the  letter  S,  and  also 
the  participles  of  every  verb  now  generally  used,  and  unless  accompanied 
by  a  particular  caution.  No  word  has  been  admitted  which  is  not  now  of 
polite  or  popular  use,  and 'no  word  has  been  excluded  which  is  required 
either  in  epistolary  composition  or  conversation.'" 

In  the  Nashville  Republican,  we  observe  the  following  notice  of  this  very 
useful  book : — 

"  In  recommending  the  '  Ladies'  Lexicon,'  therefore,  to  all  our  readers, 
male  and  female,  who  have  ever  experienced  the  difficulties  which  it  is  so 
admirably  calculated  to  remedy,  we  but  do  an  ordinary  act  of  justice  to  the 
author  and  publisher.  We  consider  the  'Ladies'  Lexicon,'  and  recom- 
mend it  to  our  readers,  as  a  work  that  possesses  superior  claims  on  their 
attention  and  patronage." 

In  giving  the  above  extracts,  we  take  occasion  to  say,  that  teachers  will 
find  the  "Ladies'  and  Gentlemen's  Lexicons"  works  admirably  adapted  to 
take  the  place,  with  advantage  to  their  pupils,  of  the  different  works  re- 
cently put  into  their  hands  under  the  name  of  Expositors,  &c. 

dj^The  above  work  has  been  introduced  as  a  Class  Book  into  many  of 
our  Academies  and  Schools  with  great  approbation. 

BIGLAND'S  NATURAL  HISTORY  of  Animals,  Birds, 
Fishes,  Reptiles  and  Insects,  illustrated  with  numerous  and  beautiful  en- 
gravings. By  John  Bigland,  author  of  a  "View  of  the  World,"  "Letters 
on  Universal  History,"  &c.  Complete  in  1  vol.  12mo. 

dj"  This  work  is  particularly  adapted  for  the  use  of  Schools  and  Fami- 
lies, forming  the  most  elegantly  written  and  complete  work  on  the  subject 
of  Natural  History  ever  published,  and  is  worthy  of  the  special  attention 
of  the  Teachers  of  all  our  Schools  and  Academies. 

BIGLAND'S  NATURAL  HISTORY  OF  ANIMALS,  illus- 
trated with  12  beautifully  coloured  engravings. 

BIGLAND'S  HISTORY  OF  BIRDS,  illustrated  with  12 
beautifully  coloured  engravings. 

PERSIA.  A  DESCRIPTION  OF.  By  Shoberl,  with  12 
coloure'd  plates. 

These  works  are  got  up  in  a  very  superior  style,  and  well  deserve  an 
introduction  to  the  shelves  of  every  family  library,  as  they  are  very  inte- 
resting, and  particularly  adapted  to  the  juvenile  class  of  readers. 


6  GRIGG  &  ELLIOT'S  SCHOOL  BOOKS. 

CONVERSATIONS  ON  ITALY,  in  English  and  French, 
designed  for  the  use  of  Schools,  Academies,  &c.  By  Miss  Julia  S.  Hawkes* 
in  1  vol.  12mo. 

(£/•  This  work  is  spoken  very  highly  of  by  Miss  C.  Beecher,  (who  form- 
erly taught  in  Hartford,  Conn.,  and  who  has  done  as  much  for  the  elevation 
of  the  female  character,  and  for  education  generally,  as  any  other  lady  in 
this  country,)  and  has  received  the  highest  recommendation  from  our  most 
distinguished  Teachers,  and  the  American  press. 

MURRAY'S  EXERCISES,  adapted  to  his  Grammar.  Grigg 
and  Elliot's  stereotype  edition. 

MURRAY'S  KEY  TO  THE  EXERCISES.  Grigg  and 
Elliot's  stereotype  edition. 

HORACE  DELPHINI.  Grigg  and  Elliot's  new  corrected 
stereotype  edition. 

The  Delphin  Classics  (of  which  Horace  Delphini  and  Virgil  Delphini 
are  two,)  were  prepared  at  the  express  command  of  the  King-of  France, 
for  the  education  of  his  son,  the  Dauphin.  They  are  not  the  result  of  the 
labours  of  a  single  man,  but  of  many  of  the  most  learned  men  of  whom 
France  could  boast;  and  consequently  they  ought, by  every  thinking  mind, 
to  be  considered  as  near  perfection  as  it  is  possible  to  approach.  They 
are  illustrated  in  the  margin  by  an  ordo,  and  at  the  foot  of  each  page  by 
most  copious  and  learned  notes  in  the  Latin  language  ;  and  they  are  sub- 
mitted to  the  judgment  of  every  teacher. 

VIRGIL  DELPHINI.  Grigg  and  Elliot's  new  corrected 
stereotype  edition. 

For  remarks  respecting  this  work  and  the  Delphin  Classics  generally, 
see  note  to  "  Horace  Delphini,"  immediately  above. 

HUTCHINSON'S  XENOPHON,  with  notes,  and  a  Latin 
translation  under  the  Greek  in  each  page,  by  Thomas  Hutchinson,  A.  M. 

This  edition  of  the  above  valuable  work  is  printed  on  a  large  and  bold 
Greek  type ;  and  has,  in  order  to  insure  its  accuracy,  been  stereotyped. 
The  classical  elegance  and  well-known  celebrity  of  Xenophon  demand  of 
every  teacher,  that  he  should  place  it  unmutilated  and  complete  in  the 
hands  of  his  scholars,  instead  of  being  content  with  the  meagre  extracts 
which  are  made  from  it  in  many  of  the  Greek  compilations  for  schools  of 
the  day. 

r/2&.^ 


;W  VALUABLE  WORKS 

FOR 

PUBLIC  AND  PRIVATE  LIBRARIES, 
PUBLISHED  BY  GRIGS  &  ELLIOT, 

•And  for  Sale  by  Booksellers  and  Country  Merchants 
generally  throughout  the  United  States. 

SPLENDID  LIBRARY  EDITIONS,  &c. 

Crabbe,  Heber  and  Pollok's  Poetical  Works,  steel  portraits,  complete  in  1 

vol.  8vo.,  bound,  library  style. 

The  same  work,  calf  extra,  embossed  gilt,  and  calf  extra  gilt. 
Byron's  Works,  complete  in  1  vol.  8vo.,  including  all  his  suppressed  and 

attributed  poems,  bound,  lib.  style. 

The  same  work,  calf  extra,  embossed  gilt,  and  calf  extra  gilt 
Cowper  and  Thomson's  Prose  and  Poetical  Works,  complete  in  1  vol.  8vo., 

bound,  library  style. 

The  same  work,  calf  extra,  embossed  gilt,  and  calf  extra  gilt. 
Rogers,  Campbell,  Montgomery,  Lamb  and  Kirk  White's  Poetical  Works, 

complete  in  1  vol.  8vo.,  bound,  library  style. 
The  same  work,  calf  extra,  embossed  gilt,  and  calf  extra  gilt. 
Milton,  Young,  Gray,  Beattie  and  Collins'  Poetical  Works,  complete  in  1 

vol.  8vo.,  bound,  library  style. 

The  same  work,  calf  extra,  embossed  gilt,  and  calf  extra  gilt. 
Mrs.  Hemans'  Poetical  Works,  complete  in  1  vol.  8vo.,  bound,  lib.  style. 
The  same  work,  calf  extra,  embossed  gilt,  and  calf  extra  gilt. 

tfj*  This  is  a  new  and  complete  edition,  with  a  splendid  engraved  like- 
ness of  Mrs.  Hemans,  on  steel,  and  contains  all  the  Poems  in  the  last  Lon- 
don and  American  editions. 
McMahon's  American  Gardener,  9th  editipn,  greatly  improved,  8vo.,  fine 

edition.      v?   r 
Goldsmith's  Animated  Nature,  beautifully  illustrated,  2  vols.  8vo.,  about 

300  cuts. 
Laurence  Sterne's  Works,  with  a  Life  of  the  Author,  written  by  himself, 

8vo.,  engraved  portrait. 

Burder's  Village  Sermons.    For  Family  Reading. 
Josephus'  Works,  2  vols.  8vo.,  sheep,  gilt. 

(£/•  The  only  readable  edition  published  in  this  country. 
Say's  Political  Economy,  8vo.,  new  edition. 
Mason's  Popular  System  of  Farriery,  new  edition. 

7 


8  GRIGG  &  ELLIOT'S  MISCELLANEOUS  BOOKS. 

Hind's  Popular  System  of  Farriery,  new  edition. 

The  Stock  Raiser's  Manual,  by  W.  Youatt,  with  plates. 

The  Importance  of  Family  Religion,  by  Rev.  S.  G.  Winchester,  1  vol.  12mo. 

Seneca's  Morals.    "  Should  be  found  in  every  library." 

Shoberl's  History  of  Persia,  with  12  fine  coloured  plates,  fancy  paper. 

Bigland's  Natural  History  of  Animals,  12  fine  coloured  plates,  fancy  paper. 

Bigland's  Natural  History  of  Birds,  Fishes,  &c.,  12  coloured  plates,  fancy 

paper. 

Dictionary  of  Select  and  Popular  Quotations,  9th  edition. 
The  American  Chesterfield,  containing  a  complete  Treatise  on  Carving, 

with  cuts. 

The  Southern  and  Western  Songster,  plate. 
The  Daughter's  Own  Book. 
Bennett's  Letters  to  Young  Ladies. 

The  Gentlemen  and  Ladies'  Book  of  Politeness,  and  Propriety  of  Deport- 
ment, by  Mrs.  Celnart. 
The  Life  of  General  Jackson. 
Winchester's  Family  Prayers,  fine  edition. 

The  New  Testament,  royal  8vo.,  large  type,  new  edition,  for  Family  use. 
Letters  from  a  Father  to  his  Sons  in  College,  by  Samuel  Miller,  D.  D. 
Bigland'.s  Natural  History,  with  24  coloured  plates,  half  mor.  ext.  gilt  ed., 

and  plain  School  edition. 
Shakspeare's  Plays,  various  editions. 
Weems'  Life  of  Marion. 

Do.          do.     Washington. 
Polyglott  Bible,  18mo.,  plain  sheep,  rolled  ed. 

Do.  do.      morocco  tucks,  gt.  ed. 

Do.  do.      plain  Eng.  calf,  gilt  ed. 

Do.  do.      Eng.  calf,  super  ex.  do. 

Do.  do.      Turkey,  mor.  gilt  ed. 

Pearl  Pocket  Bible,  best  ed.  published,  plain  sheep. 

Do.  do.  do.         mor.  tucks,  gt.  ed. 

Do.  do.  do.         plain  Eng.  calf,  gt.  ed. 

Do.  do.  do.         calf,  sup.  extra  gt. 

Do.  do.  do.         Tur.  mor.,  extra  gt.  ed. 

(£/•  All  the  above  Bibles  are  in  the  best  Philadelphia  binding. 

IC73  Public,  private,  and  social  libraries,  and  all  who  purchase 
to  sell  again,  supplied  on  the  most  reasonable  terms  with  every 
article  in  the  Book  and  Stationery  line ;  including  new  novels, 
and  all  new  works  in  evervdgpartment  of  literature  and  science. 

All  orders  will  be  tn^y^r^delvend  promptly  attended  to. 

UNIVERSITY 

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RUSOHENBEHGEH'S 


FIRST   BOOKS 

OP 

INATUKAL    HISTORY,! 

FOR  SCHOOLS,  COLLEGES,  AND  FAMIUi-s. 

1.  ELEMENTS  OF 

ANATOMY  AND  PHYSIOLOGY. 

2.  ELEMENTS  OF 

MAMMALOGY, 

The   Natural   History   of  Quadrupeds, 

8..  ELEMENTS  • 

ORNITHOLOGY, 

The  Natural  History  of  Birds. 

4.  ELEMENTS  ? 

HERPETOLOGY  AND  ICHTHYOLOGY  I] 

The  Natural  History  of  Reptiles  and  Fishes 

5.  ELEMENTS  OF 

CONCHOLOGY, 

The  Natural  History  of  Shells  and  Mol!u«ca. 

6.  ELEMENT?  ' 

EN  TO  MO  LOGY, 

The  Natural   History  of  Insects, 

7.  ELEMENTS  OF 

BOTAIY, 

The   Natural    History   of   Plants. 

8.  ELEMENTS  OF 

GEOLOGY, 

The  Natural  History  of  the  Earth's  SUtictnrc. 

rs  have  been  issued,  and  have  already  met  with  the  most  flatter-   !; 
Jig  reception  ever  extended  to  any  work  issued  from  the  American  press,    j 
Introduced  into  the  Public  Schools  of  Pennsylvania,  and  in  nearly  all  the 
fi'^t  class  seminaries  of  learning  in  the  United  States. 

'• 


